Bump to version v7.0.1

circleci: remove linux distro releases
Prefer the linux static binary for x64
2020-05-18 13:05:09 -05:00 · 2020-05-18 13:05:09 -05:00 · 2020-05-18 13:05:09 -05:00 · 2020-05-18 13:05:09 -05:00 · 2020-05-16 11:35:32 -05:00 · 2020-05-12 13:31:37 -05:00
106 changed files with 6043 additions and 2570 deletions
@@ -1,66 +1,69 @@
 version: 2

-build-distro-bin: &build-distro-bin
-  machine: true
-  steps:
-    - checkout
-    # cannot interpolate env var and use as a cache key so just copy the Dockerfile to another filename
-    - run: cp docker/distro_release/Dockerfile.$CIRCLE_JOB docker/distro_release/Dockerfile
-    - restore_cache:
-        keys:
-        - v1-{{ .Environment.CIRCLE_JOB }}-image-{{ checksum "docker/distro_release/Dockerfile" }}
-    - restore_cache:
-        keys:
-        - v1-{{ .Environment.CIRCLE_JOB }}-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-    - run:
-        name: load or build docker image
-        command: |
-          if [[ -e ~/image.tar ]]; then
-            docker load -i ~/image.tar
-          else
-            docker build --rm=false -t $CIRCLE_JOB -f docker/distro_release/Dockerfile.$CIRCLE_JOB docker/distro_release/
-            docker save $CIRCLE_JOB > ~/image.tar
-          fi
-    - run:
-        name: build binary
-        command: |
-          docker run -it \
-            -v $HOME/.stack:/root/.stack \
-            -v $(pwd):/source \
-            -v $HOME/bin/:/root/.local/bin/ \
-            $CIRCLE_JOB build --allow-different-user --install-ghc --copy-bins
-          # volumes owned by root if chown is not done the save_cache step fails silently
-          sudo chown -R circleci:circleci ~/.stack .stack-work
-    - run:
-        name: compress binary
-        command: |
-          mkdir -p /tmp/workspace/bin
-          cd /tmp/workspace/bin
-          tar cvJf postgrest-$CIRCLE_TAG-$CIRCLE_JOB.tar.xz -C ~/bin postgrest
-    - persist_to_workspace:
-        root: /tmp/workspace
-        paths:
-          - bin/*
-    - save_cache:
-        paths:
-          - ~/image.tar
-        key: v1-{{ .Environment.CIRCLE_JOB }}-image-{{ checksum "docker/distro_release/Dockerfile" }}
-    - save_cache:
-        paths:
-          - "~/.stack"
-          - ".stack-work"
-        key: v1-{{ .Environment.CIRCLE_JOB }}-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-
 jobs:
+  build-cache:
+    docker:
+      - image: circleci/buildpack-deps:trusty
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
+      - run:
+          name: install stack & dependencies
+          command: |
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
+            sudo apt-get update
+            sudo apt-get install -y libgmp-dev
+            sudo apt-get install -y --only-upgrade binutils
+            sudo apt-get install -y postgresql-client
+            stack setup
+      - run:
+          name: build src and tests dependencies
+          command: |
+            stack build --fast -j1 --only-dependencies
+            stack build --fast --test --no-run-tests --only-dependencies
+      - save_cache:
+          paths:
+            - "~/.stack"
+            - ".stack-work"
+          key: v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
+      - run:
+          name: build src and tests
+          command: |
+            stack build --fast -j1
+            stack build --fast --test --no-run-tests
+
+  style:
+    docker:
+      - image: nixos/nix:2.3
+    steps:
+      - checkout
+      - run:
+          name: Install linting and styling scripts
+          command: nix-env -f default.nix -iA lint style
+      - run:
+          name: Run linter
+          command: |
+            echo 'Note: For checking this locally, use `make lint`. Or, if using `nix`, run `nix-shell --run postgrest-lint`'
+            postgrest-lint
+      - run:
+          name: Run style check
+          command: |
+            echo 'Note: For checking this locally, use `make style`. Or, if using `nix`, run `nix-shell --run postgrest-style`'
+            postgrest-style-check
+
  build-test-9.4:
    docker:
      - image: circleci/buildpack-deps:trusty
        environment:
          - PGHOST=localhost
-      - image: circleci/postgres:9.4.14
+      - image: circleci/postgres:9.4.26
        environment:
          - POSTGRES_USER=circleci
          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
    steps:
      - checkout
      - restore_cache:
@@ -74,15 +77,18 @@ jobs:
      - run:
          name: install stack & dependencies
          command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.9.3/stack-1.9.3-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.9.3-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
            sudo apt-get update
            sudo apt-get install -y libgmp-dev
            sudo apt-get install -y --only-upgrade binutils
            sudo apt-get install -y postgresql-client
            stack setup
-            rm -rf $(stack path --dist-dir) $(stack path --local-install-root)
-            stack install hlint stylish-haskell
+      - run:
+          name: build src and tests dependencies
+          command: |
+            stack build --fast -j1 --only-dependencies
+            stack build --fast --test --no-run-tests --only-dependencies
      - run:
          name: build src and tests
          command: |
@@ -93,27 +99,17 @@ jobs:
          command: |
            POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test
            test/io-tests.sh
-      - run:
-          name: run linter
-          command: git ls-files | grep '\.l\?hs$' | xargs stack exec -- hlint -X QuasiQuotes -X NoPatternSynonyms "$@"
-      - run:
-          name: run styler
-          command: git ls-files | grep '\.l\?hs$' | xargs stack exec -- stylish-haskell -i && git diff-index --exit-code HEAD --
-      - save_cache:
-          paths:
-            - "~/.stack"
-            - ".stack-work"
-          key: v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}

  build-test-9.6:
    docker:
      - image: circleci/buildpack-deps:trusty
        environment:
          - PGHOST=localhost
-      - image: circleci/postgres:9.6.2
+      - image: circleci/postgres:9.6.17
        environment:
          - POSTGRES_USER=circleci
          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
    steps:
      - checkout
      - restore_cache:
@@ -122,8 +118,8 @@ jobs:
      - run:
          name: install stack & dependencies
          command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.9.3/stack-1.9.3-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.9.3-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
            sudo apt-get update
            sudo apt-get install -y libgmp-dev
            sudo apt-get install -y postgresql-client
@@ -135,17 +131,18 @@ jobs:
            stack build --fast --test --no-run-tests
      - run:
          name: run tests
-          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test
+          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test postgrest:spec

  build-test-10:
    docker:
      - image: circleci/buildpack-deps:trusty
        environment:
          - PGHOST=localhost
-      - image: circleci/postgres:10.5
+      - image: circleci/postgres:10.12
        environment:
          - POSTGRES_USER=circleci
          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
    steps:
      - checkout
      - restore_cache:
@@ -154,8 +151,8 @@ jobs:
      - run:
          name: install stack & dependencies
          command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.9.3/stack-1.9.3-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.9.3-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
            sudo apt-get update
            sudo apt-get install -y libgmp-dev
            sudo apt-get install -y postgresql-client
@@ -167,17 +164,18 @@ jobs:
            stack build --fast --test --no-run-tests
      - run:
          name: run tests
-          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test
+          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test postgrest:spec

  build-test-11:
    docker:
      - image: circleci/buildpack-deps:trusty
        environment:
          - PGHOST=localhost
-      - image: circleci/postgres:11
+      - image: circleci/postgres:11.7
        environment:
          - POSTGRES_USER=circleci
          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
    steps:
      - checkout
      - restore_cache:
@@ -186,8 +184,8 @@ jobs:
      - run:
          name: install stack & dependencies
          command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.9.3/stack-1.9.3-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.9.3-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
            sudo apt-get update
            sudo apt-get install -y libgmp-dev
            sudo apt-get install -y postgresql-client
@@ -199,7 +197,40 @@ jobs:
            stack build --fast --test --no-run-tests
      - run:
          name: run tests
-          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test
+          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test postgrest:spec
+
+  build-test-12:
+    docker:
+      - image: circleci/buildpack-deps:trusty
+        environment:
+          - PGHOST=localhost
+      - image: circleci/postgres:12.2
+        environment:
+          - POSTGRES_USER=circleci
+          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
+      - run:
+          name: install stack & dependencies
+          command: |
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
+            sudo apt-get update
+            sudo apt-get install -y libgmp-dev
+            sudo apt-get install -y postgresql-client
+            stack setup
+      - run:
+          name: build src and tests
+          command: |
+            stack build --fast -j1
+            stack build --fast --test --no-run-tests
+      - run:
+          name: run tests
+          command: POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test postgrest:spec

  build-prof-test:
    docker:
@@ -207,10 +238,11 @@ jobs:
        environment:
          - PGHOST=localhost
          - TERM=xterm
-      - image: circleci/postgres:9.6.2
+      - image: circleci/postgres:9.6.17
        environment:
          - POSTGRES_USER=circleci
          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
    steps:
      - checkout
      - restore_cache:
@@ -219,12 +251,21 @@ jobs:
      - run:
          name: install stack & dependencies
          command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.9.3/stack-1.9.3-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.9.3-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.1.3/stack-2.1.3-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.1.3-linux-x86_64/stack /usr/bin
            sudo apt-get update
            sudo apt-get install -y libgmp-dev
            sudo apt-get install -y postgresql-client
            stack setup
+      - run:
+          name: build dependencies with profiling enabled
+          command: |
+            stack build --profile -j1  --only-dependencies
+      - save_cache:
+          paths:
+            - "~/.stack"
+            - ".stack-work"
+          key: v1-stack-prof-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
      - run:
          name: build with profiling enabled
          command: |
@@ -233,34 +274,11 @@ jobs:
          name: run memory usage tests
          command: |
            test/create_test_db "postgres://circleci@localhost" postgrest_test
-            psql "postgres:///postgrest_test" -f test/fixtures/database.sql
-            psql "postgres:///postgrest_test" -f test/fixtures/roles.sql
-            psql "postgres:///postgrest_test" -f test/fixtures/schema.sql
-            psql "postgres:///postgrest_test" -f test/fixtures/jwt.sql
-            psql "postgres:///postgrest_test" -f test/fixtures/jsonschema.sql
-            psql "postgres:///postgrest_test" -f test/fixtures/privileges.sql
            test/memory-tests.sh
-      - save_cache:
-          paths:
-            - "~/.stack"
-            - ".stack-work"
-          key: v1-stack-prof-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-
-  centos6:
-    <<: *build-distro-bin
-
-  centos7:
-    <<: *build-distro-bin
-
-  ubuntu:
-    <<: *build-distro-bin
-
-  ubuntui386:
-    <<: *build-distro-bin

  release:
    docker:
-      - image: circleci/golang:1.8
+      - image: circleci/golang:1.9
    steps:
      - attach_workspace:
          at: /tmp/workspace
@@ -284,72 +302,132 @@ jobs:
            docker tag postgrest postgrest/postgrest:latest
            docker push postgrest/postgrest:latest

+  build-nix:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Install Nix
+          command: |
+            curl -L https://nixos.org/nix/install | sh
+            echo "source $HOME/.nix-profile/etc/profile.d/nix.sh" >> $BASH_ENV
+      - run:
+          name: Install and use the Cachix binary cache
+          command: |
+            nix-env -iA cachix -f https://cachix.org/api/v1/install
+            cachix use postgrest
+      - run:
+          name: Build the dynamic PostgREST executable
+          command: |
+            # We build the dynamic postgrest executable first in order to fail fast if anything
+            # should be wrong with the source code.
+            nix-build -A postgrest
+      - restore_cache:
+          keys:
+            - v1-cabal-nix-dependencies-{{ checksum "postgrest.cabal" }}
+      - run:
+          name: Run the spec tests against all supported PostgreSQL versions
+          command: |
+            # Our utility scripts use cabal to run the tests, which will pick up all the libraries that
+            # are built with Nix. So this should only ever build the PostgREST itself and be reasonably
+            # quick. We accelerate that part further by caching `~/.cabal` and `dist-newstyle`.
+            nix-shell --run postgrest-test-spec-all
+      - save_cache:
+          paths:
+            - "~/.cabal"
+            - "dist-newstyle"
+          key: v1-cabal-nix-dependencies-{{ checksum "postgrest.cabal" }}
+      - run:
+          name: Build all derivations from default.nix and push results to Cachix
+          command: |
+            # Only push to the cache when CircleCI makes the CACHIX_SIGNING_KEY available (e.g. not for
+            # pull requests).
+            if [ -n "${CACHIX_SIGNING_KEY:-""}" ]; then
+              echo "Building and caching all derivations..."
+              nix-build | cachix push postgrest
+            else
+              echo "Building all derivations (caching skipped for outside pull requests)..."
+              nix-build
+            fi
+
+  build-static-bin:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Install Nix
+          command: |
+            curl -L https://nixos.org/nix/install | sh
+            echo "source $HOME/.nix-profile/etc/profile.d/nix.sh" >> $BASH_ENV
+      - run:
+          name: Install and use the Cachix binary cache
+          command: |
+            nix-env -iA cachix -f https://cachix.org/api/v1/install
+            cachix use postgrest
+      - run:
+          name: Build the PostgREST statically linked binary
+          command: |
+            nix-build -A postgrestStatic
+      - run:
+          name: compress binary
+          command: |
+            mkdir -p /tmp/workspace/bin
+            cd /tmp/workspace/bin
+            tar cvJf postgrest-$CIRCLE_TAG-linux-x64-static.tar.xz -C ~/project/result/bin postgrest
+      - persist_to_workspace:
+          root: /tmp/workspace
+          paths:
+            - bin/*
+
 workflows:
  version: 2
  build-test-release:
    jobs:
+      - build-cache:
+          filters:
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*/
+      - style:
+          filters:
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*/
      - build-test-9.4:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
+          requires:
+            - build-cache
      - build-test-9.6:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
+          requires:
+            - build-cache
      - build-test-10:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
+          requires:
+            - build-cache
      - build-test-11:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
+          requires:
+            - build-cache
+      - build-test-12:
+          filters:
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*/
+          requires:
+            - build-cache
      - build-prof-test:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
-      - centos6:
+      - build-static-bin:
          requires:
-            - build-test-9.4
-            - build-test-9.6
-            - build-test-10
-            - build-test-11
-            - build-prof-test
-          filters:
-            tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - centos7:
-          requires:
-            - build-test-9.4
-            - build-test-9.6
-            - build-test-10
-            - build-test-11
-            - build-prof-test
-          filters:
-            tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - ubuntu:
-          requires:
-            - build-test-9.4
-            - build-test-9.6
-            - build-test-10
-            - build-test-11
-            - build-prof-test
-          filters:
-            tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - ubuntui386:
-          requires:
-            - build-test-9.4
-            - build-test-9.6
-            - build-test-10
-            - build-test-11
+            - build-nix
            - build-prof-test
          filters:
            tags:
@@ -358,10 +436,11 @@ workflows:
              ignore: /.*/
      - release:
          requires:
-            - centos6
-            - centos7
-            - ubuntu
-            - ubuntui386
+            - build-static-bin
+          filters:
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*/
+      - build-nix:
          filters:
            tags:
              only: /v[0-9]+(\.[0-9]+)*/
@@ -0,0 +1,55 @@
+freebsd_instance:
+  image: freebsd-12-1-release-amd64
+
+build_task:
+  env:
+    ASSUME_ALWAYS_YES: YES
+  install_script:
+    ## TODO: Some of these workaround steps might be unneeded now
+    ## gmake required, otherwise bsd make is used and some cryptic "No operator" errors are shown
+    - pkg install -y gmake
+    ## gcc required, otherwise warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined]
+    - pkg install -y gcc
+    - pkg install -y libiconv
+    - pkg install -y gmp
+    - pkg install -y postgresql95-client
+    - pkg install -y pkgconf
+    - pkg install -y ghc
+    - pkg install -y hs-cabal-install
+  cabal_cache:
+    folder: ~/.cabal
+    fingerprint_script: cat postgrest.cabal
+  build_script:
+    - cabal v2-update
+    - cabal v2-build
+  binaries_artifacts:
+    path: "dist-newstyle/build/x86_64-freebsd/ghc-8.6.5/postgrest-7.0.1/x/postgrest/build/postgrest/*"
+  #binary_script:
+    #- mkdir bin
+    ## cabal v2-install --installdir=.
+    ## the installdir option is not working on this cabal version(form hs-cabal-install), so the binary must be extrated from the path
+    ## this is too brittle so for now we don't use it
+    #- ldd /tmp/cirrus-ci-build/dist-newstyle/build/x86_64-freebsd/ghc-8.6.5/postgrest-7.0.1/x/postgrest/build/postgrest/postgrest
+    #- mv /tmp/cirrus-ci-build/dist-newstyle/build/x86_64-freebsd/ghc-8.6.5/postgrest-7.0.1/x/postgrest/build/postgrest/postgrest bin/
+  ## https://cirrus-ci.org/guide/writing-tasks/#artifacts-instruction
+  #binaries_artifacts:
+    #path: bin/
+  cleanup_script:
+    - rm -rf ~/.cabal/logs
+    - rm  ~/.cabal/config
+
+#publish_task:
+  #skip: $CIRRUS_TAG == ""
+  #env:
+    #TOKEN: ENCRYPTED[c99babbf04e8a33962ffbbc75bf20d3abe408f9bede5ed5d8956cd24da6fdb34266c920984cc43f8106ef3423fba0e98]
+  #depends_on:
+    #- build
+  #script:
+    ## https://cirrus-ci.org/guide/writing-tasks/#artifacts-instruction
+    #- wget https://api.cirrus-ci.com/v1/artifact/github/$CIRRUS_REPO_FULL_NAME/build/binaries/bin/postgrest
+    #- tar cjf postgrest-$CIRRUS_TAG-freebsd.tar.xz postgrest
+    ### The CIRRUS_RELEASE env var is not the same as the tag. It's an id for the release.
+    #- curl -X POST --data-binary @$NAME \
+      #-H "Authorization:token ${TOKEN}" \
+      #-H "Content-Type:application/octet-stream" \
+      #"https://uploads.github.com/repos/$CIRRUS_REPO_FULL_NAME/releases/${CIRRUS_RELEASE}/assets?name=${NAME}"
@@ -42,14 +42,13 @@ your contributions.
 * All contributions must pass the tests before being merged. When
  you create a pull request your code will automatically be tested.

-* All code must also pass [hlint](http://community.haskell.org/~ndm/hlint/)
-  with no warnings. This helps enforce a uniform style for all
-  committers. Continuous integration will check this as well on every
-  pull request.
+* All code must also pass [hlint](http://community.haskell.org/~ndm/hlint/) and [stylish-haskell](https://github.com/jaspervdj/stylish-haskell)
+  with no warnings. This helps enforce a uniform style for all committers. Continuous integration will check this as well on every
+  pull request. There's a useful Makefile that helps with checking this locally. You can run `make commit-check` to do this manually but
+  we recommend adding it to `.git/hooks/pre-commit` to automatically check this before doing a commit.

 * For help building the Haskell code on your computer check out the [building from
-source](https://postgrest.com/en/stable/install.html#build-from-source)
-wiki page.
+  source](https://postgrest.com/en/stable/install.html#build-from-source) docs section.

 ### Running Tests

@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+patreon: postgrest
@@ -1,3 +1,7 @@
+<!--
+Before reporting a bug:
+If your database schema has changed while the PostgREST server is running, send the server a SIGUSR1 signal or restart it(http://postgrest.org/en/v5.2/admin.html#schema-reloading) to ensure the schema cache is not stale. This sometimes fixes apparent bugs.
+-->
 ### Environment

 * PostgreSQL version: (if using docker, specify the image)
@@ -12,3 +12,6 @@ site
 *~
 *#*
 .#*
+*.swp
+result*
+dist-newstyle
@@ -1,3 +1,5 @@
+## Travis is only used for building an OSX binary ,
+## no tests are run here.
 language: generic

 sudo: false
@@ -40,11 +42,15 @@ install:
  fi

 script:
+## Building the whole project can take longer than 50 minutes. Since Travis has a global timeout of 50 minutes
+## we compile for 30 minutes tops(`gtimeout 1800`) and quit compiling with no error.
+## Since we CACHE the compile results we can continue compiling from where we left off
+## on the next commit.
 - gtimeout 1800 stack build --no-terminal --only-snapshot --install-ghc || true
 - |
  if test ! "$TRAVIS_TAG"
  then
-    echo 'No tag pushed. Skipping build.'
+    echo 'No tag pushed. Skip building binary.'
  else
    stack build --no-terminal --copy-bins --local-bin-path .
  fi
@@ -59,6 +65,6 @@ script:
    END='## \['
    BODY=$(sed -n "1,/$START/d;/$END/q;p" CHANGELOG.md)
    strip postgrest
-    tar cjf postgrest-$TRAVIS_TAG-osx.tar.xz postgrest
+    tar cJf postgrest-$TRAVIS_TAG-osx.tar.xz postgrest
    ghr -t $GITHUB_TOKEN -u $OWNER -r $REPO -b "$BODY"--replace $TRAVIS_TAG postgrest-$TRAVIS_TAG-osx.tar.xz
  fi
@@ -29,16 +29,22 @@ PostgREST ongoing development is only possible thanks to our Sponsors and Backer
 ## Lead Backers

 - [Daniel Babiak](https://github.com/d-babiak)
- [Michel Pelletier](https://github.com/michelp/)
 - Evans Fernandes
+- [Jan Sommer](https://github.com/nerfpops)

 ## Backers

 - Tsingson Qin
+- Michel Pelletier
 - Jay Hannah
 - Robert Stolarz
 - Kofi Gumbs
 - Nicholas DiBiase
+- Christopher Reid
+- Nathan Bouscal
+- Daniel Rafaj
+- David Fenko
+- Remo Rechkemmer

 ## Former Backers

@@ -9,11 +9,77 @@ This project adheres to [Semantic Versioning](http://semver.org/).

 ### Fixed

+## [7.0.1] - 2020-05-18
+
+### Fixed
+
+- #1473, Fix overloaded computed columns on RPC - @wolfgangwalther
+- #1471, Fix POST, PATCH, DELETE with ?select= and return=minimal and PATCH with empty body - @wolfgangwalther
+- #1500, Fix missing `openapi-server-proxy-uri` config option - @steve-chavez
+- #1508, Fix `Content-Profile` not working for POST RPC - @steve-chavez
+- #1452, Fix PUT restriction for all columns - @steve-chavez
+
+## [7.0.0] - 2020-04-03
+
+### Added
+
+- #1417, `Accept: application/vnd.pgrst.object+json` behavior is now enforced for POST/PATCH/DELETE regardless of `Prefer: return=representation/minimal` - @dwagin
+- #1415, Add support for user defined socket permission via `server-unix-socket-mode` config option - @Dansvidania
+- #1383, Add support for HEAD request - @steve-chavez
+- #1378, Add support for `Prefer: count=planned` and `Prefer: count=estimated` on GET /table - @steve-chavez, @LorenzHenk
+- #1327, Add support for optional query parameter `on_conflict` to upsert with specified keys for POST - @ykst
+- #1430, Allow specifying the foreign key constraint name(`/source?select=fk_constraint(*)`) to disambiguate an embedding - @steve-chavez
+- #1168, Allow access to the `Authorization` header through the `request.header.authorization` GUC - @steve-chavez
+- #1435, Add `request.method` and `request.path` GUCs - @steve-chavez
+- #1088, Allow adding headers to GET/POST/PATCH/PUT/DELETE responses through the `response.headers` GUC - @steve-chavez
+- #1427, Allow overriding provided headers(Location, Content-Type, etc) through the `response.headers` GUC - @steve-chavez
+- #1450, Allow multiple schemas to be exposed in one instance. The schema to use can be selected through the headers `Accept-Profile` for GET/HEAD and `Content-Profile` for POST/PATCH/PUT/DELETE - @steve-chavez, @mahmoudkassem
+
+### Fixed
+
+- #1301, Fix self join resource embedding on PATCH - @herulume, @steve-chavez
+- #1389, Fix many to many resource embedding on RPC/PATCH - @steve-chavez
+- #1355, Allow PATCH/DELETE without `return=minimal` on tables with no select privileges - @steve-chavez
+- #1361, Fix embedding a VIEW when its source foreign key is UNIQUE - @bwbroersma
+
+### Changed
+
+- #1385, bulk RPC call now should be done by specifying a `Prefer: params=multiple-objects` header - @steve-chavez
+- #1401, resource embedding now outputs an error when multiple relationships between two tables are found - @steve-chavez
+- #1423, default Unix Socket file mode from 755 to 660 - @dwagin
+- #1430, Remove embedding with duck typed column names `GET /projects?select=client(*)`- @steve-chavez
+  + You can rename the foreign key to `client` to make this request work in the new version: `alter table projects rename constraint projects_client_id_fkey to client`
+- #1413, Change `server-proxy-uri` config option to `openapi-server-proxy-uri` - @steve-chavez
+
+## [6.0.2] - 2019-08-22
+
+### Fixed
+
+- #1369, Change `raw-media-types` to accept a string of comma separated MIME types - @Dansvidania
+- #1368, Fix long column descriptions being truncated at 63 characters in PostgreSQL 12 - @amedeedaboville
+- #1348, Go back to converting plus "+" to space " " in querystrings by default - @steve-chavez
+
+### Deprecated
+
+- #1348, Deprecate `.` symbol for disambiguating resource embedding(added in #918). The url-safe '!' should be used instead. We refrained from using `+` as part of our syntax because it conflicts with some http clients and proxies.
+
+## [6.0.1] - 2019-07-30
+
+### Added
+
+- #1349, Add user defined raw output media types via `raw-media-types` config option - @Dansvidania
+- #1243, Add websearch_to_tsquery support - @herulume
+
+### Fixed
+
+- #1336, Error when testing on Chrome/Firefox: text/html requested but a single column was not selected - @Dansvidania
+- #1334, Unable to compile v6.0.0 on windows - @steve-chavez
+
 ## [6.0.0] - 2019-06-21

 ### Added

- #1186, Add support for user defined unix socket via `server-unix-socket` config option
+- #1186, Add support for user defined unix socket via `server-unix-socket` config option - @Dansvidania
 - #690, Add `?columns` query parameter for faster bulk inserts, also ignores unspecified json keys in a payload - @steve-chavez
 - #1239, Add support for resource embedding on materialized views - @vitorbaptista
 - #1264, Add support for bulk RPC call - @steve-chavez
@@ -22,6 +88,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #790, Allow override of OpenAPI spec through `root-spec` config option - @steve-chavez
 - #1308, Accept `text/plain` and `text/html` for raw output - @steve-chavez

+
 ### Fixed

 - #1223, Fix incorrect OpenAPI externalDocs url - @steve-chavez
@@ -1,4 +1,5 @@
 Copyright (c) 2014 Joe Nelson
+Copyright (c) 2019 Steve Chavez

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
@@ -1,16 +1,19 @@
-.PHONY: check clean lint style test test-watch coverage circleci circleci-prof-test check-dburi prompt-clean prompt-long-process
+.PHONY: commit-check check clean lint style test test-watch coverage circleci circleci-prof-test check-dburi prompt-clean prompt-long-process
+
+commit-check: lint style

 check: lint style test

 clean: prompt-clean
 	stack clean --full

+# For running these you'll need to install hlint and stylish-haskell first. Run:
+# stack install hlint stylish-haskell
 lint:
 	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- hlint -X QuasiQuotes -X NoPatternSynonyms "$$@"

 style:
-	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- stylish-haskell -i
-
+	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- stylish-haskell -i && git diff-index --exit-code HEAD -- '*.hs' '*.lhs'

 test: check-dburi
 	stack test
@@ -22,14 +25,12 @@ coverage: check-dburi clean
 	stack build --coverage
 	stack test --coverage

-
 circleci: prompt-long-process
 	circleci local execute --job build-test-9.4

 circleci-prof-test: prompt-long-process
 	circleci local execute --job build-prof-test

-
 check-dburi:
 	test -n "$(POSTGREST_TEST_CONNECTION)" # Requires POSTGREST_TEST_CONNECTION environmental variable

@@ -50,13 +50,15 @@ Big thanks to our sponsors! You can join them by supporting PostgREST on [Patreo
    ```bash
    postgrest --help
    ```
+## [Documentation](http://postgrest.org)
+
+Latest documentation is at [postgrest.org](http://postgrest.org). You can contribute to the docs in [PostgREST/postgrest-docs](https://github.com/PostgREST/postgrest-docs).

 ## Performance

 TLDR; subsecond response times for up to 2000 requests/sec on Heroku
-free tier. If you're used to servers written in interpreted languages
-(or named after precious gems), prepare to be pleasantly surprised by
-PostgREST performance.
+free tier. If you're used to servers written in interpreted languages, 
+prepare to be pleasantly surprised by PostgREST performance.

 Three factors contribute to the speed. First the server is written
 in [Haskell](https://www.haskell.org/) using the
@@ -10,7 +10,7 @@
    },
    "POSTGREST_VER": {
      "description": "Version of PostgREST to deploy",
-      "value": "6.0.0"
+      "value": "7.0.1"
    },
    "DB_URI": {
      "description": "Database connection string, e.g. postgres://user:pass@xxxxxxx.rds.amazonaws.com/mydb",
@@ -1,24 +1,20 @@
+## AppVeyor is only used for building a Windows binary, no tests are run here.
 platform: x64
+image: Visual Studio 2015

 cache:
 - "c:\\sr"
 - .stack-work
+- "c:\\Users\\appveyor\\AppData\\Local\\Programs\\stack"

 environment:
  global:
    STACK_ROOT: "c:\\sr"
    GOPATH: c:\gopath
+    TMP: "c:\\tmp"

 test: off

-skip_non_tags: true
-
-skip_branch_with_pr: true
-
-branches:
-  only:
-    - master
-
 install:
 - set PATH=C:\Program Files\PostgreSQL\9.6\bin\;%PATH%
 - curl -sS -ostack.zip -L --insecure http://www.stackage.org/stack/windows-x86_64
@@ -28,11 +24,13 @@ install:

 build_script:
 - stack setup --no-terminal > nul
- stack build -j1 --copy-bins --local-bin-path .
+# Appveyor has a timeout of 60 mins, building can take longer, limit the time and make sure this succeeds,
+# previous work will get cached and finish on next commit
+- bash -lc "timeout 2700 'C:\projects\postgrest\stack.exe' build -j1 --copy-bins --local-bin-path . || true"

 artifacts:
 - path: postgrest.exe

 deploy_script:
- 7z a -tzip postgrest-%APPVEYOR_REPO_TAG_NAME%-windows-x64.zip postgrest.exe
- bash -lc "exec 0</dev/null && cd $APPVEYOR_BUILD_FOLDER && ghr -t $GITHUB_TOKEN -u $APPVEYOR_ACCOUNT_NAME -r $APPVEYOR_PROJECT_NAME -b \"$(sed -n \"1,/$(echo $APPVEYOR_REPO_TAG_NAME | cut -c2-)/d;/## \[/q;p\" CHANGELOG.md)\" --replace $APPVEYOR_REPO_TAG_NAME postgrest-$APPVEYOR_REPO_TAG_NAME-windows-x64.zip"
+- IF DEFINED APPVEYOR_REPO_TAG_NAME 7z a -tzip postgrest-%APPVEYOR_REPO_TAG_NAME%-windows-x64.zip postgrest.exe
+- IF DEFINED APPVEYOR_REPO_TAG_NAME bash -lc " exec 0</dev/null && cd $APPVEYOR_BUILD_FOLDER && ghr -t $GITHUB_TOKEN -u $APPVEYOR_ACCOUNT_NAME -r $APPVEYOR_PROJECT_NAME -b \"$(sed -n \"1,/$(echo $APPVEYOR_REPO_TAG_NAME | cut -c2-)/d;/## \[/q;p\" CHANGELOG.md)\" --replace $APPVEYOR_REPO_TAG_NAME postgrest-$APPVEYOR_REPO_TAG_NAME-windows-x64.zip"
@@ -0,0 +1,109 @@
+let
+  name =
+    "postgrest";
+
+  compiler =
+    "ghc883";
+
+  # PostgREST source files, filtered based on the rules in the .gitignore files
+  # and file extensions. We want to include as litte as possible, as the files
+  # added here will increase the space used in the Nix store and trigger the
+  # build of new Nix derivations when changed.
+  src =
+    pkgs.lib.sourceFilesBySuffices
+      (pkgs.gitignoreSource ./.)
+      [ ".cabal" ".hs" ".lhs" "LICENSE" ];
+
+  # Commit of the Nixpkgs repository that we want to use.
+  nixpkgsVersion =
+    import nix/nixpkgs-version.nix;
+
+  # Nix files that describe the Nixpkgs repository. We evaluate the expression
+  # using `import` below.
+  nixpkgs =
+    builtins.fetchTarball {
+      url = "https://github.com/nixos/nixpkgs/archive/${nixpkgsVersion.rev}.tar.gz";
+      sha256 = nixpkgsVersion.tarballHash;
+    };
+
+  overlays =
+    [
+      (import nix/overlays/postgresql-legacy.nix)
+      (import nix/overlays/gitignore.nix)
+      (import nix/overlays/haskell-packages)
+    ];
+
+  # Evaluated expression of the Nixpkgs repository.
+  pkgs =
+    import nixpkgs { inherit overlays; };
+
+  postgresqlVersions =
+    [
+      pkgs.postgresql_12
+      pkgs.postgresql_11
+      pkgs.postgresql_10
+      pkgs.postgresql_9_6
+      pkgs.postgresql_9_5
+      pkgs.postgresql_9_4
+    ];
+
+  patches =
+    pkgs.callPackage nix/patches {};
+
+  # Base dynamic derivation for the PostgREST package.
+  drv =
+    pkgs.haskellPackages.callCabal2nix name src {};
+
+  # Static derivation for the PostgREST executable.
+  drvStatic =
+    import nix/static { inherit nixpkgs name src compiler patches; };
+
+  lib =
+    pkgs.haskell.lib;
+in
+rec {
+  inherit nixpkgs pkgs;
+
+  # Derivation for the PostgREST Haskell package, including the executable,
+  # libraries and documentation. We disable running the test suite on Nix
+  # builds, as they require a database to be set up.
+  postgrestWithLib =
+    lib.dontCheck drv;
+
+  # Derivation for just the PostgREST binary, where we strip all dynamic
+  # libraries and documentation, leaving only the executable. Note that the
+  # executable is static with regards to Haskell libraries, but not system
+  # libraries like glibc and libpq.
+  postgrest =
+    lib.justStaticExecutables postgrestWithLib;
+
+  # Static executable.
+  postgrestStatic =
+    lib.justStaticExecutables (lib.dontCheck drvStatic);
+
+  # Docker image and loading script.
+  docker =
+    pkgs.callPackage nix/docker { postgrest = postgrestStatic; };
+
+  # Environment in which PostgREST can be built with cabal, useful e.g. for
+  # defining a shell for nix-shell.
+  env =
+    drv.env;
+
+  # Utility for updating the pinned version of Nixpkgs.
+  nixpkgsUpgrade =
+    pkgs.callPackage nix/nixpkgs-upgrade.nix {};
+
+  tests =
+    pkgs.callPackage nix/tests.nix
+      {
+        inherit postgresqlVersions;
+        postgrestBuildEnv = env;
+      };
+
+  style =
+    pkgs.callPackage nix/style.nix {};
+
+  lint =
+    pkgs.callPackage nix/lint.nix {};
+}
@@ -1,4 +1,7 @@
-FROM debian:stretch-slim
+# To build use:
+# docker build --build-arg POSTGREST_VERSION=<v5.2.0 or another version> -t postgrest ./docker/
+
+FROM debian:buster-slim

 ARG POSTGREST_VERSION

@@ -31,13 +34,15 @@ ENV PGRST_DB_URI= \
    PGRST_DB_EXTRA_SEARCH_PATH=public \
    PGRST_SERVER_HOST=*4 \
    PGRST_SERVER_PORT=3000 \
-    PGRST_SERVER_PROXY_URI= \
+    PGRST_OPENAPI_SERVER_PROXY_URI= \
    PGRST_JWT_SECRET= \
    PGRST_SECRET_IS_BASE64=false \
    PGRST_JWT_AUD= \
    PGRST_MAX_ROWS= \
    PGRST_PRE_REQUEST= \
-    PGRST_ROLE_CLAIM_KEY=".role"
+    PGRST_ROLE_CLAIM_KEY=".role" \
+    PGRST_ROOT_SPEC= \
+    PGRST_RAW_MEDIA_TYPES=

 RUN groupadd -g 1000 postgrest && \
    useradd -r -u 1000 -g postgrest postgrest && \
@@ -1,3 +0,0 @@
-db-uri = "postgres://app_user:password@postgres:5432/app_db"
-db-schema = "public"
-db-anon-role = "app_user"
@@ -1,18 +0,0 @@
-FROM centos:centos6
-
-RUN yum -y update
-RUN yum -y install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar
-RUN yum -y install https://download.postgresql.org/pub/repos/yum/9.3/redhat/rhel-6-x86_64/pgdg-centos93-9.3-2.noarch.rpm
-RUN yum -y install postgresql93-devel
-RUN yum clean all
-RUN curl -sSL https://get.haskellstack.org/ | sh
-
-ENV PATH $PATH:/usr/pgsql-9.3/bin
-
-# To disable warning when building
-ENV PATH $PATH:/root/.local/bin
-
-RUN mkdir /source
-WORKDIR /source
-
-ENTRYPOINT ["stack"]
@@ -2,12 +2,12 @@ FROM centos:centos7

 RUN yum -y update
 RUN yum -y install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar
-RUN yum -y install yum install https://download.postgresql.org/pub/repos/yum/9.3/redhat/rhel-7-x86_64/pgdg-centos93-9.3-2.noarch.rpm
-RUN yum -y install postgresql93-devel
+RUN yum -y install yum install https://download.postgresql.org/pub/repos/yum/10/redhat/rhel-7-x86_64/pgdg-centos10-10-2.noarch.rpm
+RUN yum -y install postgresql10-devel
 RUN yum clean all
 RUN curl -sSL https://get.haskellstack.org/ | sh

-ENV PATH $PATH:/usr/pgsql-9.3/bin
+ENV PATH $PATH:/usr/pgsql-10/bin

 # To disable warning when building
 ENV PATH $PATH:/root/.local/bin
@@ -1,5 +1,7 @@
 FROM ubuntu:16.04

+## TODO pin the stack version
+#
 RUN BUILD_DEPS="curl ca-certificates build-essential" && \
    apt-get -qq update && \
    apt-get -qqy --no-install-recommends install \
@@ -1,4 +1,6 @@
-FROM 32bit/ubuntu:16.04
+FROM i386/ubuntu:16.04
+
+## TODO pin the stack version

 RUN BUILD_DEPS="curl ca-certificates build-essential" && \
    apt-get -qq update && \
@@ -7,7 +7,7 @@ db-extra-search-path = "$(PGRST_DB_EXTRA_SEARCH_PATH)"
 server-host = "$(PGRST_SERVER_HOST)"
 server-port = "$(PGRST_SERVER_PORT)"

-server-proxy-uri = "$(PGRST_SERVER_PROXY_URI)"
+openapi-server-proxy-uri = "$(PGRST_OPENAPI_SERVER_PROXY_URI)"
 jwt-secret = "$(PGRST_JWT_SECRET)"
 secret-is-base64 = "$(PGRST_SECRET_IS_BASE64)"
 jwt-aud = "$(PGRST_JWT_AUD)"
@@ -15,3 +15,5 @@ role-claim-key = "$(PGRST_ROLE_CLAIM_KEY)"

 max-rows = "$(PGRST_MAX_ROWS)"
 pre-request = "$(PGRST_PRE_REQUEST)"
+root-spec = "$(PGRST_ROOT_SPEC)"
+raw-media-types = "$(PGRST_RAW_MEDIA_TYPES)"
@@ -12,25 +12,16 @@ import Control.AutoUpdate       (defaultUpdateSettings, mkAutoUpdate,
 import Control.Retry            (RetryStatus, capDelay,
                                 exponentialBackoff, retrying,
                                 rsPreviousDelay)
+import Data.Either.Combinators  (whenLeft)
 import Data.IORef               (IORef, atomicWriteIORef, newIORef,
                                 readIORef)
 import Data.String              (IsString (..))
-import Data.Text                (pack, replace, strip, stripPrefix,
-                                 unpack)
-import Data.Text.Encoding       (decodeUtf8, encodeUtf8)
-import Data.Text.IO             (hPutStrLn, readFile)
+import Data.Text                (pack, replace, strip, stripPrefix)
+import Data.Text.IO             (hPutStrLn)
 import Data.Time.Clock          (getCurrentTime)
-import Network.Socket           (Family (AF_UNIX),
-                                 SockAddr (SockAddrUnix), Socket,
-                                 SocketType (Stream), bind, close,
-                                 defaultProtocol, listen,
-                                 maxListenQueue, socket)
 import Network.Wai.Handler.Warp (defaultSettings, runSettings,
-                                 runSettingsSocket, setHost, setPort,
-                                 setServerName)
-import System.Directory         (removeFile)
+                                 setHost, setPort, setServerName)
 import System.IO                (BufferMode (..), hSetBuffering)
-import System.IO.Error          (isDoesNotExistError)

 import PostgREST.App         (postgrest)
 import PostgREST.Config      (AppConfig (..), configPoolTimeout',
@@ -42,13 +33,16 @@ import PostgREST.OpenAPI     (isMalformedProxyUri)
 import PostgREST.Types       (ConnectionStatus (..), DbStructure,
                              PgVersion (..), Schema,
                              minimumPgVersion)
-import Protolude             hiding (hPutStrLn, replace)
+import Protolude             hiding (hPutStrLn, head, replace, toS)
+import Protolude.Conv        (toS)


 #ifndef mingw32_HOST_OS
 import System.Posix.Signals
+import UnixSocket
 #endif

+
 {-|
  The purpose of this worker is to fill the refDbStructure created in 'main'
  with the 'DbStructure' returned from calling 'getDbStructure'. This method
@@ -70,11 +64,11 @@ import System.Posix.Signals
 connectionWorker
  :: ThreadId -- ^ This thread is killed if pg version is unsupported
  -> P.Pool   -- ^ The PostgreSQL connection pool
-  -> Schema   -- ^ Schema PostgREST is serving up
+  -> [Schema] -- ^ Schemas PostgREST is serving up
  -> IORef (Maybe DbStructure) -- ^ mutable reference to 'DbStructure'
  -> IORef Bool                -- ^ Used as a binary Semaphore
  -> IO ()
-connectionWorker mainTid pool schema refDbStructure refIsWorkerOn = do
+connectionWorker mainTid pool schemas refDbStructure refIsWorkerOn = do
  isWorkerOn <- readIORef refIsWorkerOn
  unless isWorkerOn $ do
    atomicWriteIORef refIsWorkerOn True
@@ -90,7 +84,7 @@ connectionWorker mainTid pool schema refDbStructure refIsWorkerOn = do
        NotConnected                -> return ()               -- Unreachable
        Connected actualPgVersion   -> do                      -- Procede with initialization
          result <- P.use pool $ do
-            dbStructure <- HT.transaction HT.ReadCommitted HT.Read $ getDbStructure schema actualPgVersion
+            dbStructure <- HT.transaction HT.ReadCommitted HT.Read $ getDbStructure schemas actualPgVersion
            liftIO $ atomicWriteIORef refDbStructure $ Just dbStructure
          case result of
            Left e -> do
@@ -159,10 +153,12 @@ main = do
  -- readOptions builds the 'AppConfig' from the config file specified on the
  -- command line
  conf <- loadDbUriFile =<< loadSecretFile =<< readOptions
-  let host = configHost conf
+  let schemas = toList $ configSchemas conf
+      host = configHost conf
      port = configPort conf
-      proxy = configProxyUri conf
+      proxy = configOpenAPIProxyUri conf
      maybeSocketAddr = configSocket conf
+      socketFileMode = configSocketMode conf
      pgSettings = toS (configDatabase conf) -- is the db-uri
      roleClaimKey = configRoleClaimKey conf
      appSettings =
@@ -171,16 +167,18 @@ main = do
        . setServerName (toS $ "postgrest/" <> prettyVersion) $
        defaultSettings

+
+  whenLeft socketFileMode panic
+
  -- Checks that the provided proxy uri is formated correctly
  when (isMalformedProxyUri $ toS <$> proxy) $
    panic
      "Malformed proxy uri, a correct example: https://example.com:8443/basePath"

  -- Checks that the provided jspath is valid
-  when (isLeft roleClaimKey) $
+  whenLeft roleClaimKey $
    panic $ show roleClaimKey

-  --
  -- create connection pool with the provided settings, returns either
  -- a 'Connection' or a 'ConnectionError'. Does not throw.
  pool <- P.acquire (configPool conf, configPoolTimeout' conf, pgSettings)
@@ -199,7 +197,7 @@ main = do
  connectionWorker
    mainTid
    pool
-    (configSchema conf)
+    schemas
    refDbStructure
    refIsWorkerOn
  --
@@ -221,7 +219,7 @@ main = do
    Catch $ connectionWorker
              mainTid
              pool
-              (configSchema conf)
+              schemas
              refDbStructure
              refIsWorkerOn
    ) Nothing
@@ -240,22 +238,20 @@ main = do
          (connectionWorker
             mainTid
             pool
-             (configSchema conf)
+             schemas
             refDbStructure
             refIsWorkerOn)
-    in case maybeSocketAddr of
-         Nothing -> do
-             -- run the postgrest application
-             putStrLn $ ("Listening on port " :: Text) <> show (configPort conf)
-             runSettings appSettings postgrestApplication
-         Just socketAddr -> do
-             -- run postgrest application with user defined socket
-             sock <- createAndBindSocket (unpack socketAddr)
-             listen sock maxListenQueue
-             putStrLn $ ("Listening on unix socket " :: Text) <> show socketAddr
-             runSettingsSocket appSettings sock postgrestApplication
-             -- clean socket up when done
-             close sock
+
+  -- run the postgrest application with user defined socket. Only for UNIX systems.
+#ifndef mingw32_HOST_OS
+  whenJust maybeSocketAddr $
+    runAppInSocket appSettings postgrestApplication socketFileMode
+#endif
+
+  -- run the postgrest application
+  whenNothing maybeSocketAddr $ do
+    putStrLn $ ("Listening on port " :: Text) <> show (configPort conf)
+    runSettings appSettings postgrestApplication

 {-|
  The purpose of this function is to load the JWT secret from a file if
@@ -324,14 +320,11 @@ loadDbUriFile conf = extractDbUri mDbUri
        Just filename -> strip <$> readFile (toS filename)
    setDbUri dbUri = conf {configDatabase = dbUri}

-createAndBindSocket :: FilePath -> IO Socket
-createAndBindSocket filePath = do
-  deleteSocketFileIfExist filePath
-  sock <- socket AF_UNIX Stream defaultProtocol
-  bind sock $ SockAddrUnix filePath
-  return sock
-  where
-    deleteSocketFileIfExist path = removeFile path `catch` handleDoesNotExist
-    handleDoesNotExist e
-      | isDoesNotExistError e = return ()
-      | otherwise = throwIO e
+-- Utilitarian functions.
+whenJust :: Applicative f => Maybe a -> (a -> f ()) -> f ()
+whenJust (Just x) f = f x
+whenJust Nothing _  = pass
+
+whenNothing :: Applicative f => Maybe a -> f () -> f ()
+whenNothing Nothing f = f
+whenNothing _       _ = pass
@@ -0,0 +1,40 @@
+module UnixSocket (
+  runAppInSocket
+)where
+
+import Network.Socket           (Family (AF_UNIX),
+                                 SockAddr (SockAddrUnix), Socket,
+                                 SocketType (Stream), bind, close,
+                                 defaultProtocol, listen,
+                                 maxListenQueue, socket)
+import Network.Wai              (Application)
+import Network.Wai.Handler.Warp
+import System.Directory         (removeFile)
+import System.IO.Error          (isDoesNotExistError)
+import System.Posix.Files       (setFileMode)
+import System.Posix.Types       (FileMode)
+
+import Protolude
+
+createAndBindSocket :: FilePath -> Maybe FileMode -> IO Socket
+createAndBindSocket socketFilePath maybeSocketFileMode = do
+  deleteSocketFileIfExist socketFilePath
+  sock <- socket AF_UNIX Stream defaultProtocol
+  bind sock $ SockAddrUnix socketFilePath
+  mapM_ (setFileMode socketFilePath) maybeSocketFileMode
+  return sock
+  where
+    deleteSocketFileIfExist path = removeFile path `catch` handleDoesNotExist
+    handleDoesNotExist e
+      | isDoesNotExistError e = return ()
+      | otherwise = throwIO e
+
+-- run the postgrest application with user defined socket.
+runAppInSocket :: Settings -> Application -> Either Text FileMode -> FilePath -> IO ()
+runAppInSocket settings app socketFileMode sockPath = do
+  sock <- createAndBindSocket sockPath (rightToMaybe socketFileMode)
+  putStrLn $ ("Listening on unix socket " :: Text) <> show sockPath
+  listen sock maxListenQueue
+  runSettingsSocket settings sock app
+  -- clean socket up when done
+  close sock
@@ -0,0 +1,163 @@
+# Nix development and build environment
+
+With Nix it's possible to quickly and reliably recreate the full environments
+for developing, testing and building PostgREST.
+
+## Getting started with Nix
+
+You'll need to [get Nix](https://nixos.org/download.html). The installer will
+create your Nix store in the `/nix/` directory, where all build artifacts and
+their dependencies will be stored. It will also link the Nix executables like
+`nix-env`, `nix-build` and `nix-shell` into your PATH. Nix will manage all
+other PostgREST dependencies from here on out. To clean up older build
+artifacts from the `/nix/store`, you can run `nix-collect-garbage`.
+
+## Building PostgREST
+
+To build PostgREST from your local checkout of the repository, run:
+
+```bash
+nix-build --attr postgrest
+
+```
+
+This will create a `result` directory that contains the PostgREST binary at
+`result/bin/postgrest`. The `--attr` parameter (or short: `-A`) tells Nix to
+build the `postgrest` attribute from the Nix expression it finds in our
+`default.nix` (see below for details). Nix will take care of getting the right
+GHC version and all the build dependencies.
+
+## Developing
+
+A development environment for PostgREST is available with `nix-shell`. The
+following command will put you into a new shell that has GHC and Cabal on the
+PATH:
+
+```bash
+nix-shell
+
+```
+
+Within `nix-shell`, you can run Cabal commands as usual. You can also run
+stack with the `--nix` option, which causes stack to pick up the non-Haskell
+dependencies from the same pinned Nixpkgs version that the Nix builds use.
+
+## Aside: Working with `nix-shell` and the PostgREST utility scripts
+
+The PostgREST utilities available in `nix-shell` all have names that begin
+with `postgrest-`, so you can use tab completion (`postgrest-<tab>`) in 
+`nix-shell` to see all that are available:
+
+```
+# Note: The utilities listed here might not be up to date.
+[nix-shell:~/Projects/postgrest]$ postgrest-
+postgrest-lint                         postgrest-test-spec-postgresql-10.12
+postgrest-style                        postgrest-test-spec-postgresql-11.7
+postgrest-style-check                  postgrest-test-spec-postgresql-12.2
+postgrest-test-all                     postgrest-test-spec-postgresql-9.4.24
+postgrest-test-spec                    postgrest-test-spec-postgresql-9.5.21
+postgrest-test-spec-all                postgrest-test-spec-postgresql-9.6.17
+
+[nix-shell:~/Projects/postgrest]$
+
+```
+
+To run one-off commands, you can also use `nix-shell --run <command>`, which
+will lauch the Nix shell, run that one command and exit. Note that the tab
+completion will not work with `nix-shell --run`, as Nix has yet to evaluate
+our Nix expressions to see which utilities are available.
+
+```
+$ nix-shell --run postgrest-style
+
+# Note that you need to quote any arguments that you would like to pass to
+# the command to be run in nix-shell:
+$ nix-shell --run "postgrest-foo --bar"
+
+```
+
+A third option is to install utilities that you use very often locally:
+
+```
+$ nix-env -f default.nix -iA style
+
+# `postgrest-style` can now be run directly:
+$ postgrest-style
+
+```
+
+Note that this does not yet work for all utilities (e.g. `postgrest-test-spec` currently
+needs to be run within the Nix shell environment).
+
+If you use `nix-shell` very often, you might like to use https://github.com/xzfc/cached-nix-shell,
+which skips evaluating all our Nix expressions if nothing changed, reducing startup time for the
+shell considerably.
+
+## Testing
+
+In nix-shell, you'll find utility scripts that make it very easy to run the
+Haskell test suite, including setting up all required dependencies and
+temporary test databases:
+
+```bash
+# Run the tests against the most recent version of PostgreSQL:
+$ nix-shell --run postgrest-test-spec
+
+# Run the tests against all supported versions of PostgreSQL:
+$ nix-shell --run postgrest-test-spec-all
+
+# Run the tests against a specific version of PostgreSQL (use tab-completion in
+# nix-shell to see all available versions):
+$ nix-shell --run postgrest-test-spec-postgresql-9.5.21
+
+```
+
+## Linting and styling code
+
+The nix-shell also contains scripts for linting and styling the PostgREST
+source code:
+
+```bash
+# Linting
+$ nix-shell --run postgrest-lint
+
+# Styling / auto-formatting code
+$ nix-shell --run postgrest-style
+
+```
+
+## Tour
+
+The following is not required for working on PostgREST with Nix, but it will
+give you some more background and details on how it works.
+
+### `default.nix`
+
+[`default.nix`](../default.nix) is our 'respository expression' that pulls all
+the pieces that we define with Nix together. It returns a set (like a dict in
+other programming languages), where each attribute is a derivation that Nix
+knows how to build, like the `postgrest` attribute from earlier.
+
+Internally, our `default.nix` uses the `pkgs.callPackage` function to import
+the modules that we defined in the `nix` directory. It automatically passes the
+arguments those modules require if they are available in `pkgs` (this means
+that `pkgs` is defined in terms of itself, better not to think too much about
+that).
+
+We also use `default.nix` to load our pinned version of the `nixpkgs`
+repository. This set of packages will always be the same, independently from
+where or when you use it. The pinned version can be upgraded with the small
+`nixpkgs-upgrade` utility. Running `nixpkgs-upgrade > nix/nixpkgs-version.nix`
+in `nix-shell` will upgrade the pinned version to the latest `nixpkgs-unstable`
+version.
+
+### `shell.nix`
+
+[`shell.nix`](../shell.nix) defines an environment in which PostgREST can be
+built and developed. It extends the build enviroment from our `postgrest`
+attribute with useful utilities that will be put on the PATH in `nix-shell`.
+
+### `nix/overlays`
+
+Our overlays to the Nix package set are defined here. They allow us to tweak our
+`pkgs` in `default.nix` by adding new packages or overriding existing ones.
@@ -0,0 +1,63 @@
+{ postgrest, dockerTools, writeShellScriptBin }:
+let
+  image =
+    tag:
+      dockerTools.buildImage {
+        inherit tag;
+
+        name = "postgrest/postgrest";
+        contents = postgrest;
+
+        # Set the current time as the image creation date. This makes the build
+        # non-reproducible, but that should not be an issue for us.
+        created = "now";
+
+        extraCommands =
+          ''
+            mkdir etc
+            cp ${./postgrest.conf} etc/postgrest.conf
+          '';
+
+        config = {
+          Cmd = [ "/bin/postgrest" "/etc/postgrest.conf" ];
+          Env = [
+            "PGRST_DB_URI=postgresql://?user=postgres"
+            "PGRST_DB_SCHEMA=public"
+            "PGRST_DB_ANON_ROLE="
+            "PGRST_DB_POOL=100"
+            "PGRST_DB_EXTRA_SEARCH_PATH=public"
+            "PGRST_SERVER_HOST=*4"
+            "PGRST_SERVER_PORT=3000"
+            "PGRST_OPENAPI_SERVER_PROXY_URI="
+            "PGRST_JWT_SECRET="
+            "PGRST_SECRET_IS_BASE64=false"
+            "PGRST_JWT_AUD="
+            "PGRST_MAX_ROWS="
+            "PGRST_PRE_REQUEST="
+            "PGRST_ROLE_CLAIM_KEY=.role"
+            "PGRST_ROOT_SPEC="
+            "PGRST_RAW_MEDIA_TYPES="
+          ];
+          User = "1000";
+          ExposedPorts = {
+            "3000/tcp" = {};
+          };
+        };
+      };
+in
+rec {
+  imageLatest =
+    image "latest";
+
+  imageWithVersion =
+    image "v${postgrest.version}";
+
+  load =
+    writeShellScriptBin "postgrest-docker-load"
+      ''
+        set -euo pipefail
+
+        docker load -i ${imageLatest}
+        docker load -i ${imageWithVersion}
+      '';
+}
@@ -0,0 +1,19 @@
+db-uri = "$(PGRST_DB_URI)"
+db-schema = "$(PGRST_DB_SCHEMA)"
+db-anon-role = "$(PGRST_DB_ANON_ROLE)"
+db-pool = "$(PGRST_DB_POOL)"
+db-extra-search-path = "$(PGRST_DB_EXTRA_SEARCH_PATH)"
+
+server-host = "$(PGRST_SERVER_HOST)"
+server-port = "$(PGRST_SERVER_PORT)"
+
+openapi-server-proxy-uri = "$(PGRST_OPENAPI_SERVER_PROXY_URI)"
+jwt-secret = "$(PGRST_JWT_SECRET)"
+secret-is-base64 = "$(PGRST_SECRET_IS_BASE64)"
+jwt-aud = "$(PGRST_JWT_AUD)"
+role-claim-key = "$(PGRST_ROLE_CLAIM_KEY)"
+
+max-rows = "$(PGRST_MAX_ROWS)"
+pre-request = "$(PGRST_PRE_REQUEST)"
+root-spec = "$(PGRST_ROOT_SPEC)"
+raw-media-types = "$(PGRST_RAW_MEDIA_TYPES)"
@@ -0,0 +1,12 @@
+{ writeShellScriptBin, git, silver-searcher, hlint }:
+
+writeShellScriptBin "postgrest-lint"
+  ''
+    set -euo pipefail
+
+    rootdir="$(${git}/bin/git rev-parse --show-toplevel)"
+
+    # Lint Haskell files
+    ${silver-searcher}/bin/ag -l -g '\.l?hs$' "$rootdir" \
+      | xargs ${hlint}/bin/hlint -X QuasiQuotes -X NoPatternSynonyms
+  ''
@@ -0,0 +1,41 @@
+{ curl
+, jq
+, writeShellScriptBin
+, nix
+}:
+# Utility script for pinning the latest unstable version of Nixpkgs.
+
+# Instead of pinning Nixpkgs based on the huge Git repository, we reference a
+# specific tarball that only contains the source of the revision that we want
+# to pin.
+let
+  name =
+    "nixpkgs-upgrade";
+
+  refUrl =
+    https://api.github.com/repos/nixos/nixpkgs/git/ref/heads/nixpkgs-unstable;
+
+  githubV3Header =
+    "Accept: application/vnd.github.v3+json";
+
+  tarballUrlBase =
+    https://github.com/nixos/nixpkgs/archive/;
+in
+writeShellScriptBin name
+  ''
+    set -euo pipefail
+
+    commitHash="$(${curl}/bin/curl "${refUrl}" -H "${githubV3Header}" | ${jq}/bin/jq -r .object.sha)"
+    tarballUrl="${tarballUrlBase}$commitHash.tar.gz"
+    tarballHash="$(${nix}/bin/nix-prefetch-url --unpack "$tarballUrl")"
+    currentDate="$(date --iso)"
+
+    cat << EOF
+    # Pinned version of Nixpkgs, generated with ${name}.
+    {
+      date = "$currentDate";
+      rev = "$commitHash";
+      tarballHash = "$tarballHash";
+    }
+    EOF
+  ''
@@ -0,0 +1,6 @@
+# Pinned version of Nixpkgs, generated with nixpkgs-upgrade.
+{
+  date = "2020-04-19";
+  rev = "10100a97c8964e82b30f180fda41ade8e6f69e41";
+  tarballHash = "011f36kr3c1ria7rag7px26bh73d1b0xpqadd149bysf4hg17rln";
+}
@@ -0,0 +1,19 @@
+self: super:
+# Overlay that adds the `gitignoreSource` function from Hercules-CI.
+# This function is useful for filtering which files are added to the Nix store.
+# See: https://github.com/hercules-ci/gitignore.nix
+
+# To update to a newer revision, the simplest way is to add a new commit hash
+# from GitHub under `rev` and to then add the hash that Nix suggests on first
+# use.
+{
+  gitignoreSource =
+    let
+      gitignoreSrc = super.fetchFromGitHub {
+        owner = "hercules-ci";
+        repo = "gitignore";
+        rev = "2ced4519f865341adcb143c5d668f955a2cb997f";
+        sha256 = "sha256:0fc5bgv9syfcblp23y05kkfnpgh3gssz6vn24frs8dzw39algk2z";
+      };
+    in (super.callPackage gitignoreSrc {}).gitignoreSource;
+}
@@ -0,0 +1,10 @@
+The `.nix` files in this directory pin specific versions of Haskell packages
+from Hackage. They were generated with `cabal2nix`, e.g.:
+
+```bash
+cabal2nix cabal://protolude > protolude.nix
+
+```
+
+Those overrides might become obsolete as the pinned versions are adopted into
+our pinned version of nixpkgs.
@@ -0,0 +1,11 @@
+self: super:
+
+{
+  haskellPackages =
+    super.haskellPackages.override {
+      overrides =
+        final: prev: rec {
+          protolude = prev.callPackage ./protolude.nix {};
+        };
+    };
+}
@@ -0,0 +1,43 @@
+{ mkDerivation
+, array
+, async
+, base
+, bytestring
+, containers
+, deepseq
+, ghc-prim
+, hashable
+, mtl
+, mtl-compat
+, stdenv
+, stm
+, text
+, transformers
+, transformers-compat
+}:
+mkDerivation {
+  pname = "protolude";
+  version = "0.3.0";
+  sha256 = "4083385a9e03fab9201f63ce198b9ced3fbc1c50d6d42574db5e36c757bedcac";
+  isLibrary = true;
+  isExecutable = true;
+  libraryHaskellDepends = [
+    array
+    async
+    base
+    bytestring
+    containers
+    deepseq
+    ghc-prim
+    hashable
+    mtl
+    mtl-compat
+    stm
+    text
+    transformers
+    transformers-compat
+  ];
+  homepage = "https://github.com/sdiehl/protolude";
+  description = "A small prelude";
+  license = stdenv.lib.licenses.mit;
+}
@@ -0,0 +1,20 @@
+self: super:
+# Overlay that adds legacy versions of PostgreSQL that are supported by
+# PostgREST.
+{
+  # PostgreSQL 9.4 was removed from Nixpkgs with
+  # https://github.com/NixOS/nixpkgs/commit/8e2fc57a80d761c46702c3250e61c1bffe021e25
+  # We pin its parent commit 3b5b9a7 to get the last version that was available.
+  postgresql_9_4 =
+    let
+      rev = "3b5b9a73f59ff93d50156e250203410bdd07f4e0";
+      tarballHash = "0kr25xqbv1ldp72jbmml21pc5hl7xcfqhclv5qxa5f860jddjznk";
+
+      pinnedPkgs =
+        builtins.fetchTarball {
+          url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
+          sha256 = tarballHash;
+        };
+    in
+      (import pinnedPkgs {}).pkgs.postgresql_9_4;
+}
@@ -0,0 +1,25 @@
+{ runCommand }:
+
+{
+  # Apply patches to a directory.
+  applyPatches =
+    name: path: patches:
+      runCommand name { inherit patches; }
+        ''
+          set -eou pipefail
+
+          cp -r ${path} $out
+          chmod -R u+w $out
+
+          for patch in $patches; do
+            echo "Applying patch $patch"
+            patch -d "$out" -p1 < "$patch"
+          done
+        '';
+
+  static-haskell-nix-postgrest-libpq =
+    ./static-haskell-nix-postgrest-libpq.patch;
+
+  nixpkgs-revert-ghc-bootstrap =
+    ./nixpkgs-revert-ghc-bootstrap.patch;
+}
@@ -0,0 +1,125 @@
+From 93cc144b215654ca9cb0d2bcb58bb8922895ccab Mon Sep 17 00:00:00 2001
+From: Remo <remo>
+Date: Sat, 25 Apr 2020 17:31:55 +0200
+Subject: [PATCH] Revert "ghc: 8.6.3-binary -> 8.6.5-binary"
+
+This reverts commit 3c7ef6bcd85e3e133ac6f2ab5e238934d56d902e.
+---
+ .../{8.6.5-binary.nix => 8.6.3-binary.nix}    | 13 ++++++------
+ pkgs/top-level/haskell-packages.nix           | 20 +++++++++----------
+ 2 files changed, 16 insertions(+), 17 deletions(-)
+ rename pkgs/development/compilers/ghc/{8.6.5-binary.nix => 8.6.3-binary.nix} (95%)
+
+diff --git a/pkgs/development/compilers/ghc/8.6.5-binary.nix b/pkgs/development/compilers/ghc/8.6.3-binary.nix
+similarity index 95%
+rename from pkgs/development/compilers/ghc/8.6.5-binary.nix
+rename to pkgs/development/compilers/ghc/8.6.3-binary.nix
+index 97793d912895..9e0fd12b96cf 100644
+--- a/pkgs/development/compilers/ghc/8.6.5-binary.nix
+++ b/pkgs/development/compilers/ghc/8.6.3-binary.nix
+@@ -27,19 +27,18 @@ let
+ in
+ 
+ stdenv.mkDerivation rec {
+-  version = "8.6.5";
+  version = "8.6.3";
+ 
+   name = "ghc-${version}-binary";
+ 
+-  # https://downloads.haskell.org/~ghc/8.6.5/
+   src = fetchurl ({
+     i686-linux = {
+-      url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-i386-deb9-linux.tar.xz";
+-      sha256 = "1p2h29qghql19ajk755xa0yxkn85slbds8m9n5196ris743vkp8w";
+      url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-i386-deb8-linux.tar.xz";
+      sha256 = "0bw8a7fxcbskf93rb4m542ff66vrmx5i5kj77qx37cbhijx70w5m";
+     };
+     x86_64-linux = {
+-      url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-x86_64-deb9-linux.tar.xz";
+-      sha256 = "1pqlx6rdjs2110g0y1i9f8x18lmdizibjqd15f5xahcz39hgaxdw";
+      url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-x86_64-deb8-linux.tar.xz";
+      sha256 = "1m9gaga2pzi2cx5gvasg0rx1dlvr68gmi20l67652kag6xjsa719";
+     };
+     aarch64-linux = {
+       url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-aarch64-ubuntu18.04-linux.tar.xz";
+@@ -47,7 +46,7 @@ stdenv.mkDerivation rec {
+     };
+     x86_64-darwin = {
+       url = "http://haskell.org/ghc/dist/${version}/ghc-${version}-x86_64-apple-darwin.tar.xz";
+-      sha256 = "0s9188vhhgf23q3rjarwhbr524z6h2qga5xaaa2pma03sfqvvhfz";
+      sha256 = "1hbzk57v45176kxcx848p5jn5p1xbp2129ramkbzsk6plyhnkl3r";
+     };
+   }.${stdenv.hostPlatform.system}
+     or (throw "cannot bootstrap GHC on this platform"));
+diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
+index aa7ef02a3886..712a98e147e0 100644
+--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
+@@ -4,7 +4,7 @@ let
+   # These are attributes in compiler and packages that don't support integer-simple.
+   integerSimpleExcludes = [
+     "ghc822Binary"
+-    "ghc865Binary"
+    "ghc863Binary"
+     "ghc844"
+     "ghcjs"
+     "ghcjs86"
+@@ -42,7 +42,7 @@ in {
+ 
+     ghc822Binary = callPackage ../development/compilers/ghc/8.2.2-binary.nix { };
+ 
+-    ghc865Binary = callPackage ../development/compilers/ghc/8.6.5-binary.nix { };
+    ghc863Binary = callPackage ../development/compilers/ghc/8.6.3-binary.nix { };
+ 
+     ghc844 = callPackage ../development/compilers/ghc/8.4.4.nix {
+       bootPkgs = packages.ghc822Binary;
+@@ -57,31 +57,31 @@ in {
+       llvmPackages = pkgs.llvmPackages_6;
+     };
+     ghc881 = callPackage ../development/compilers/ghc/8.8.1.nix {
+-      bootPkgs = packages.ghc865Binary;
+      bootPkgs = packages.ghc863Binary;
+       inherit (buildPackages.python3Packages) sphinx;
+       buildLlvmPackages = buildPackages.llvmPackages_7;
+       llvmPackages = pkgs.llvmPackages_7;
+     };
+     ghc882 = callPackage ../development/compilers/ghc/8.8.2.nix {
+-      bootPkgs = packages.ghc865Binary;
+      bootPkgs = packages.ghc863Binary;
+       inherit (buildPackages.python3Packages) sphinx;
+       buildLlvmPackages = buildPackages.llvmPackages_7;
+       llvmPackages = pkgs.llvmPackages_7;
+     };
+     ghc883 = callPackage ../development/compilers/ghc/8.8.3.nix {
+-      bootPkgs = packages.ghc865Binary;
+      bootPkgs = packages.ghc863Binary;
+       inherit (buildPackages.python3Packages) sphinx;
+       buildLlvmPackages = buildPackages.llvmPackages_7;
+       llvmPackages = pkgs.llvmPackages_7;
+     };
+     ghc8101 = callPackage ../development/compilers/ghc/8.10.1.nix {
+-      bootPkgs = packages.ghc865Binary;
+      bootPkgs = packages.ghc863Binary;
+       inherit (buildPackages.python3Packages) sphinx;
+       buildLlvmPackages = buildPackages.llvmPackages_9;
+       llvmPackages = pkgs.llvmPackages_9;
+     };
+     ghcHEAD = callPackage ../development/compilers/ghc/head.nix {
+-      bootPkgs = packages.ghc883; # no binary yet
+      bootPkgs = packages.ghc863Binary;
+       inherit (buildPackages.python3Packages) sphinx;
+       buildLlvmPackages = buildPackages.llvmPackages_9;
+       llvmPackages = pkgs.llvmPackages_9;
+@@ -118,9 +118,9 @@ in {
+       compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-8.2.x.nix { };
+       packageSetConfig = bootstrapPackageSet;
+     };
+-    ghc865Binary = callPackage ../development/haskell-modules {
+-      buildHaskellPackages = bh.packages.ghc865Binary;
+-      ghc = bh.compiler.ghc865Binary;
+    ghc863Binary = callPackage ../development/haskell-modules {
+      buildHaskellPackages = bh.packages.ghc863Binary;
+      ghc = bh.compiler.ghc863Binary;
+       compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-8.6.x.nix { };
+       packageSetConfig = bootstrapPackageSet;
+     };
@@ -0,0 +1,25 @@
+From bb4c1e27e391eff01591fe60830ff68a9ada41ef Mon Sep 17 00:00:00 2001
+From: Remo <remo>
+Date: Wed, 22 Apr 2020 11:58:07 +0200
+Subject: [PATCH] Add postgrest libpq linking fix
+
+---
+ survey/default.nix | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/survey/default.nix b/survey/default.nix
+index b28606c..fd7cde7 100644
+--- a/survey/default.nix
+++ b/survey/default.nix
+@@ -1052,6 +1052,11 @@ let
+                   super.squeal-postgresql
+                   [ final.openssl ]
+                   "--libs openssl";
+              postgrest =
+                addStaticLinkerFlagsWithPkgconfig
+                  super.postgrest
+                  [ final.openssl ]
+                  "--libs openssl";
+ 
+               xml-to-json =
+                 addStaticLinkerFlagsWithPkgconfig
@@ -0,0 +1,90 @@
+{ mkDerivation
+, array
+, base
+, base-compat
+, base-orphans
+, binary
+, bytestring
+, containers
+, deepseq
+, Diff
+, directory
+, filepath
+, integer-logarithms
+, mtl
+, optparse-applicative
+, parsec
+, pretty
+, process
+, QuickCheck
+, stdenv
+, stm
+, tagged
+, tar
+, tasty
+, tasty-golden
+, tasty-hunit
+, tasty-quickcheck
+, temporary
+, text
+, time
+, transformers
+, tree-diff
+, unix
+}:
+mkDerivation {
+  pname = "Cabal";
+  version = "3.0.0.0";
+  sha256 = "5143ec26d740c1a508c93a8860e64407e7546c29b9817db20ff1595c1968d287";
+  setupHaskellDepends = [ mtl parsec ];
+  libraryHaskellDepends = [
+    array
+    base
+    binary
+    bytestring
+    containers
+    deepseq
+    directory
+    filepath
+    mtl
+    parsec
+    pretty
+    process
+    text
+    time
+    transformers
+    unix
+  ];
+  testHaskellDepends = [
+    array
+    base
+    base-compat
+    base-orphans
+    binary
+    bytestring
+    containers
+    deepseq
+    Diff
+    directory
+    filepath
+    integer-logarithms
+    optparse-applicative
+    pretty
+    process
+    QuickCheck
+    stm
+    tagged
+    tar
+    tasty
+    tasty-golden
+    tasty-hunit
+    tasty-quickcheck
+    temporary
+    text
+    tree-diff
+  ];
+  doCheck = false;
+  homepage = "http://www.haskell.org/cabal/";
+  description = "A framework for packaging Haskell software";
+  license = stdenv.lib.licenses.bsd3;
+}
@@ -0,0 +1,89 @@
+# Turn a Haskell source package (given its name and source) into a derivation
+# for a fully static executable.
+{ nixpkgs, compiler, name, src, patches }:
+let
+  # The nh2/static-haskell-nix project does all the hard work for us for
+  # building static Haskell executables. We apply a patch for PostgREST below
+  # until the respective pull request is merged. See:
+  # https://github.com/nh2/static-haskell-nix/pull/91
+  # statix-haskell-nix builds everything based on Musl instead of glibc, so
+  # there will be a _lot_ to rebuild if you don't use a binary cache.
+  static-haskell-nix =
+    let
+      rev = "749707fc90b781c3e653e67917a7d571fe82ae7b";
+    in
+      builtins.fetchTarball {
+        url = "https://github.com/nh2/static-haskell-nix/archive/${rev}.tar.gz";
+        sha256 = "155spda2lww378bhx68w6dxwqd5y6s9kin3qbgl2m23r3vmk3m3w";
+      };
+
+  patched-static-haskell-nix =
+    patches.applyPatches "patched-static-haskell-nix" static-haskell-nix
+      [
+        patches.static-haskell-nix-postgrest-libpq
+      ];
+
+  haskellPackagesOverrides =
+    lib: final: prev:
+      {
+        # Add our source package.
+        "${name}" = prev.callCabal2nix name src {};
+
+        # cabal2nix depends on Cabal 3.0.*, while our pinned version of Nixpkgs
+        # only provides 2.4 or 3.2. So we pinned 3.0.0.0 in ./Cabal.nix
+        cabal2nix =
+          prev.cabal2nix.overrideScope
+            (self: super: { Cabal = self.callPackage ./Cabal.nix {}; });
+
+        # Pinned version of protolude.
+        protolude =
+          prev.callPackage ../overlays/haskell-packages/protolude.nix {};
+
+        # The tests for the packages below took a long time on static
+        # builds, so we disable them for now - to be investigated.
+        happy = lib.dontCheck prev.happy;
+      };
+
+  # This overlay adds our source package and applies adjustments to the
+  # derivation of other packages that it depends on. The overlay applies to
+  # Haskell packages for the given compiler, which we will later use
+  # with the static-haskell-nix survey.
+  overlay =
+    self: super:
+    # Override the set of Haskell packages at
+    # pkgs.haskell.packages."${compiler}".
+      {
+        haskell = super.haskell // {
+          packages = super.haskell.packages // {
+            "${compiler}" =
+              super.haskell.packages."${compiler}".override
+                { overrides = haskellPackagesOverrides self.haskell.lib; };
+          };
+        };
+      };
+
+  patchedNixpkgs =
+    patches.applyPatches "patched-nixpkgs" nixpkgs
+      [
+        patches.nixpkgs-revert-ghc-bootstrap
+      ];
+
+  # Apply our overlay to the given pkgs.
+  normalPkgs =
+    (import patchedNixpkgs {}).appendOverlays [ overlay ];
+
+  # Each version of GHC needs a specific version of Cabal.
+  defaultCabalPackageVersionComingWithGhc =
+    {
+      ghc883 = "Cabal_3_2_0_0";
+    }."${compiler}";
+
+  # Let the static-haskell-nix project do the hard work of deriving a set of
+  # fully static Haskell executables, including one for the our source package
+  # that we added through the overlay.
+  survey =
+    import "${patched-static-haskell-nix}/survey"
+      { inherit normalPkgs compiler defaultCabalPackageVersionComingWithGhc; };
+in
+  # Return the fully static derivation of our source package.
+survey.haskellPackages."${name}"
@@ -0,0 +1,37 @@
+{ writeShellScriptBin
+, git
+, nixpkgs-fmt
+, silver-searcher
+, stylish-haskell
+, buildEnv
+}:
+let
+  style =
+    writeShellScriptBin "postgrest-style"
+      ''
+        set -euo pipefail
+
+        rootdir="$(${git}/bin/git rev-parse --show-toplevel)"
+
+        # Format Nix files
+        ${nixpkgs-fmt}/bin/nixpkgs-fmt "$rootdir" > /dev/null 2> /dev/null
+
+        # Format Haskell files
+        ${silver-searcher}/bin/ag -l -g '\.l?hs$' "$rootdir" \
+          | xargs ${stylish-haskell}/bin/stylish-haskell -i
+      '';
+
+  check =
+    writeShellScriptBin "postgrest-style-check"
+      ''
+        set -euo pipefail
+
+        ${style}/bin/${style.name}
+
+        ${git}/bin/git diff-index --exit-code HEAD -- '*.hs' '*.lhs' '*.nix'
+      '';
+in
+buildEnv {
+  name = "postgrest-style";
+  paths = [ style check ];
+}
@@ -0,0 +1,90 @@
+# Utilities for running the PostgREST test suite
+
+{ buildEnv
+, cabal-install
+, git
+, lib
+, postgrestBuildEnv
+, postgresqlVersions
+, runtimeShell
+, writeShellScript
+, writeShellScriptBin
+}:
+let
+  # Wrap the `test/with_tmp_db` script with the required dependencies from Nix.
+  withTmpDb =
+    postgresql:
+      writeShellScript "postgrest-test-${postgresql.name}"
+        ''
+          set -euo pipefail
+
+          export PATH=${postgresql}/bin:${git}/bin:${runtimeShell}/bin:"$PATH"
+
+          exec ${../test/with_tmp_db} "$@"
+        '';
+
+  # Script to run the Haskell test suite against a specific version of
+  # PostgreSQL.
+  testSpec =
+    name: postgresql:
+      writeShellScriptBin name
+        ''
+          set -euo pipefail
+
+          cat << EOF
+
+          Running spec against ${postgresql.name}...
+
+          EOF
+
+          # TODO: Make this work outside nix-shell when installed with nix-env.
+          # Probably using postgrestBuildEnv somehow?
+          ${withTmpDb postgresql} ${cabal-install}/bin/cabal v2-test \
+            --test-show-detail=direct
+
+          cat << EOF
+
+          Done running spec against ${postgresql.name}.
+
+          EOF
+        '';
+
+  # The PostgreSQL version that we run the tests against by default.
+  defaultPostgresql =
+    builtins.head postgresqlVersions;
+
+  defaultTestSpec =
+    testSpec "postgrest-test-spec" defaultPostgresql;
+
+  # Create a `testSpec` for each PostgreSQL version that we want to test
+  # against.
+  testSpecVersions =
+    map
+      (postgresql: testSpec "postgrest-test-spec-${postgresql.name}" postgresql)
+      postgresqlVersions;
+
+  # Helper script for running the tests against all PostgreSQL versions.
+  testSpecAllVersions =
+    let
+      testRunners =
+        map (test: "${test}/bin/${test.name}") testSpecVersions;
+    in
+      writeShellScriptBin "postgrest-test-spec-all"
+        ''
+          set -euo pipefail
+
+          ${lib.concatStringsSep "\n" testRunners}
+        '';
+in
+  # Create an environment that contains all the utility scripts for running tests
+  # that we defined above.
+buildEnv {
+  name =
+    "postgrest-tests";
+
+  paths =
+    [
+      defaultTestSpec
+      testSpecAllVersions
+    ] ++ testSpecVersions;
+}
@@ -1,13 +1,13 @@
 name:               postgrest
-version:            6.0.0
+version:            7.0.1
 synopsis:           REST API for any Postgres database
 description:        Reads the schema of a PostgreSQL database and creates RESTful routes
                    for the tables and views, supporting all HTTP verbs that security
                    permits.
 license:            MIT
 license-file:       LICENSE
-author:             Joe Nelson, Adam Baker
-maintainer:         Steve Chávez <stevechavezast@gmail.com>
+author:             Joe Nelson, Adam Baker, Steve Chavez
+maintainer:         Steve Chavez <stevechavezast@gmail.com>
 category:           Executable, PostgreSQL, Network APIs
 homepage:           https://postgrest.org
 bug-reports:        https://github.com/PostgREST/postgrest/issues
@@ -36,20 +36,23 @@ library
                      PostgREST.OpenAPI
                      PostgREST.Parsers
                      PostgREST.QueryBuilder
+                      PostgREST.Statements
                      PostgREST.RangeQuery
                      PostgREST.Types
  other-modules:      Paths_postgrest
+                      PostgREST.Private.Common
+                      PostgREST.Private.QueryFragment
  hs-source-dirs:     src
-  build-depends:      base                      >= 4.9 && < 4.13
+  build-depends:      base                      >= 4.9 && < 4.15
                    , HTTP                      >= 4000.3.7 && < 4000.4
                    , Ranged-sets               >= 0.3 && < 0.5
-                    , aeson                     >= 0.11.3 && < 1.5
+                    , aeson                     >= 1.4.7 && < 1.5
                    , ansi-wl-pprint            >= 0.6.7 && < 0.7
-                    , base64-bytestring         >= 1 && < 1.1
+                    , base64-bytestring         >= 1 && < 1.2
                    , bytestring                >= 0.10.8 && < 0.11
                    , case-insensitive          >= 1.2 && < 1.3
                    , cassava                   >= 0.4.5 && < 0.6
-                    , configurator-pg           >= 0.1 && < 0.2
+                    , configurator-pg           >= 0.2 && < 0.3
                    , containers                >= 0.5.7 && < 0.7
                    , contravariant             >= 1.4 && < 1.6
                    , contravariant-extras      >= 0.3.3 && < 0.4
@@ -58,23 +61,23 @@ library
                    , gitrev                    >= 1.2 && < 1.4
                    , hasql                     >= 1.4 && < 1.5
                    , hasql-pool                >= 0.5 && < 0.6
-                    , hasql-transaction         >= 0.7.2 && < 0.8
+                    , hasql-transaction         >= 0.7.2 && < 1.1
                    , heredoc                   >= 0.2 && < 0.3
                    , http-types                >= 0.12.2 && < 0.13
-                    , insert-ordered-containers >= 0.1 && < 0.3
+                    , insert-ordered-containers >= 0.2.2 && < 0.3
                    , interpolatedstring-perl6  >= 1 && < 1.1
-                    , jose                      >= 0.7 && < 0.8
-                    , lens                      >= 4.14 && < 4.18
-                    , lens-aeson                >= 1.0.1 && < 1.1
-                    , network-uri               >= 2.6.1 && < 2.7
-                    , optparse-applicative      >= 0.13 && < 0.15
+                    , jose                      >= 0.8.1 && < 0.9
+                    , lens                      >= 4.14 && < 4.20
+                    , lens-aeson                >= 1.0.1 && < 1.2
+                    , network-uri               >= 2.6.1 && < 2.8
+                    , optparse-applicative      >= 0.13 && < 0.16
                    , parsec                    >= 3.1.11 && < 3.2
-                    , protolude                 >= 0.2.2 && < 0.3
-                    , regex-tdfa                >= 1.2.2 && < 1.3
+                    , protolude                 >= 0.3 && < 0.4
+                    , regex-tdfa                >= 1.2.2 && < 1.4
                    , scientific                >= 0.3.4 && < 0.4
-                    , swagger2                  >= 2.1.4 && < 2.4
+                    , swagger2                  >= 2.4 && < 2.7
                    , text                      >= 1.2.2 && < 1.3
-                    , time                      >= 1.6 && < 1.9
+                    , time                      >= 1.6 && < 1.11
                    , unordered-containers      >= 0.2.8 && < 0.3
                    , vector                    >= 0.11 && < 0.13
                    , wai                       >= 3.2.1 && < 3.3
@@ -85,33 +88,45 @@ library
  default-extensions: OverloadedStrings
                      QuasiQuotes
                      NoImplicitPrelude
+  ghc-options:        -O2 -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path
+          -- -fno-spec-constr may help keep compile time memory use in check,
+          --   see https://gitlab.haskell.org/ghc/ghc/issues/16017#note_219304
+          -- -optP-Wno-nonportable-include-path
+          --   prevents build failures on case-insensitive filesystems (macos),
+          --   see https://github.com/commercialhaskell/stack/issues/3918

 executable postgrest
  main-is:            Main.hs
  hs-source-dirs:     main
-  build-depends:      base              >= 4.9 && < 4.13
+  build-depends:      base              >= 4.9 && < 4.15
                    , auto-update       >= 0.1.4 && < 0.2
-                    , base64-bytestring >= 1 && < 1.1
+                    , base64-bytestring >= 1 && < 1.2
                    , bytestring        >= 0.10.8 && < 0.11
                    , directory         >= 1.2.6 && < 1.4
+                    , either            >= 4.4.1 && < 5.1
                    , hasql             >= 1.4 && < 1.5
                    , hasql-pool        >= 0.5 && < 0.6
-                    , hasql-transaction >= 0.7.2 && < 0.8
-                    , network           < 2.9
+                    , hasql-transaction >= 0.7.2 && < 1.1
+                    , network           < 3.2
                    , postgrest
-                    , protolude         >= 0.2.2 && < 0.3
+                    , protolude         >= 0.3 && < 0.4
                    , retry             >= 0.7.4 && < 0.9
                    , text              >= 1.2.2 && < 1.3
-                    , time              >= 1.6 && < 1.9
-                    , warp              >= 3.2.12 && < 3.3
+                    , time              >= 1.6 && < 1.11
+                    , wai               >= 3.2.1 && < 3.3
+                    , warp              >= 3.2.12 && < 3.4
  default-language:   Haskell2010
  default-extensions: OverloadedStrings
                      QuasiQuotes
                      NoImplicitPrelude
  ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I2"
+                      -O2 -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path

  if !os(windows)
    build-depends: unix
+    other-modules: UnixSocket

 test-suite spec
  type:               exitcode-stdio-1.0
@@ -124,6 +139,7 @@ test-suite spec
                      Feature.ConcurrentSpec
                      Feature.CorsSpec
                      Feature.DeleteSpec
+                      Feature.EmbedDisambiguationSpec
                      Feature.ExtraSearchPathSpec
                      Feature.InsertSpec
                      Feature.JsonOperatorSpec
@@ -141,15 +157,18 @@ test-suite spec
                      Feature.StructureSpec
                      Feature.UnicodeSpec
                      Feature.UpsertSpec
+                      Feature.RawOutputTypesSpec
+                      Feature.HtmlRawOutputSpec
+                      Feature.MultipleSchemaSpec
                      SpecHelper
                      TestTypes
  hs-source-dirs:     test
-  build-depends:      base              >= 4.9 && < 4.13
-                    , aeson             >= 0.11.3 && < 1.5
+  build-depends:      base              >= 4.9 && < 4.15
+                    , aeson             >= 1.4.7 && < 1.5
                    , aeson-qq          >= 0.8.1 && < 0.9
                    , async             >= 2.1.1 && < 2.3
                    , auto-update       >= 0.1.4 && < 0.2
-                    , base64-bytestring >= 1 && < 1.1
+                    , base64-bytestring >= 1 && < 1.2
                    , bytestring        >= 0.10.8 && < 0.11
                    , case-insensitive  >= 1.2 && < 1.3
                    , cassava           >= 0.4.5 && < 0.6
@@ -157,21 +176,21 @@ test-suite spec
                    , contravariant     >= 1.4 && < 1.6
                    , hasql             >= 1.4 && < 1.5
                    , hasql-pool        >= 0.5 && < 0.6
-                    , hasql-transaction >= 0.7.2 && < 0.8
+                    , hasql-transaction >= 0.7.2 && < 1.1
                    , heredoc           >= 0.2 && < 0.3
                    , hspec             >= 2.3 && < 2.8
-                    , hspec-wai         >= 0.7 && < 0.10
-                    , hspec-wai-json    >= 0.7 && < 0.10
+                    , hspec-wai         >= 0.10 && < 0.11
+                    , hspec-wai-json    >= 0.10 && < 0.11
                    , http-types        >= 0.12.3 && < 0.13
-                    , lens              >= 4.14 && < 4.18
-                    , lens-aeson        >= 1.0.1 && < 1.1
+                    , lens              >= 4.14 && < 4.20
+                    , lens-aeson        >= 1.0.1 && < 1.2
                    , monad-control     >= 1.0.1 && < 1.1
                    , postgrest
                    , process           >= 1.4.2 && < 1.7
-                    , protolude         >= 0.2.2 && < 0.3
-                    , regex-tdfa        >= 1.2.2 && < 1.3
+                    , protolude         >= 0.3 && < 0.4
+                    , regex-tdfa        >= 1.2.2 && < 1.4
                    , text              >= 1.2.2 && < 1.3
-                    , time              >= 1.6 && < 1.9
+                    , time              >= 1.6 && < 1.11
                    , transformers-base >= 0.4.4 && < 0.5
                    , wai               >= 3.2.1 && < 3.3
                    , wai-extra         >= 3.0.19 && < 3.1
@@ -180,3 +199,42 @@ test-suite spec
                      QuasiQuotes
                      NoImplicitPrelude
  ghc-options:        -threaded -rtsopts -with-rtsopts=-N
+
+Test-Suite spec-querycost
+  Type:                exitcode-stdio-1.0
+  Default-Language:    Haskell2010
+  default-extensions:  OverloadedStrings, QuasiQuotes, NoImplicitPrelude
+  Hs-Source-Dirs:      test
+  Main-Is:             QueryCost.hs
+  Other-Modules:       SpecHelper
+  Build-Depends:       base              >= 4.9 && < 4.15
+                     , aeson             >= 1.4.7 && < 1.5
+                     , aeson-qq          >= 0.8.1 && < 0.9
+                     , async             >= 2.1.1 && < 2.3
+                     , auto-update       >= 0.1.4 && < 0.2
+                     , base64-bytestring >= 1 && < 1.2
+                     , bytestring        >= 0.10.8 && < 0.11
+                     , case-insensitive  >= 1.2 && < 1.3
+                     , cassava           >= 0.4.5 && < 0.6
+                     , containers        >= 0.5.7 && < 0.7
+                     , contravariant     >= 1.4 && < 1.6
+                     , hasql             >= 1.4 && < 1.5
+                     , hasql-pool        >= 0.5 && < 0.6
+                     , hasql-transaction >= 0.7.2 && < 1.1
+                     , heredoc           >= 0.2 && < 0.3
+                     , hspec             >= 2.3 && < 2.8
+                     , hspec-wai         >= 0.10 && < 0.11
+                     , hspec-wai-json    >= 0.10 && < 0.11
+                     , http-types        >= 0.12.3 && < 0.13
+                     , lens              >= 4.14 && < 4.20
+                     , lens-aeson        >= 1.0.1 && < 1.2
+                     , monad-control     >= 1.0.1 && < 1.1
+                     , postgrest
+                     , process           >= 1.4.2 && < 1.7
+                     , protolude         >= 0.3 && < 0.4
+                     , regex-tdfa        >= 1.2.2 && < 1.4
+                     , text              >= 1.2.2 && < 1.3
+                     , time              >= 1.6 && < 1.11
+                     , transformers-base >= 0.4.4 && < 0.5
+                     , wai               >= 3.2.1 && < 3.3
+                     , wai-extra         >= 3.0.19 && < 3.1
@@ -0,0 +1,23 @@
+with (import ./default.nix);
+pkgs.lib.overrideDerivation env (
+  base: {
+    buildInputs =
+      base.buildInputs ++ [
+        pkgs.cabal-install
+        pkgs.stack
+        pkgs.cabal2nix
+        pkgs.postgresql
+        nixpkgsUpgrade
+        tests
+        style
+        lint
+      ];
+
+    shellHook =
+      ''
+        # Set our pinned version of Nixpkgs in the NIX_PATH so that
+        # `stack --nix` also uses that version.
+        NIX_PATH="nixpkgs=${nixpkgs}"
+      '';
+  }
+)
@@ -3,13 +3,14 @@ Module      : PostgREST.ApiRequest
 Description : PostgREST functions to translate HTTP request to a domain type called ApiRequest.
 -}
 {-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}

 module PostgREST.ApiRequest (
  ApiRequest(..)
+, InvokeMethod(..)
 , ContentType(..)
 , Action(..)
 , Target(..)
-, PreferRepresentation (..)
 , mutuallyAgreeable
 , userApiRequest
 ) where
@@ -28,6 +29,7 @@ import qualified Data.Vector          as V
 import Control.Arrow             ((***))
 import Data.Aeson.Types          (emptyArray, emptyObject)
 import Data.List                 (last, lookup, partition)
+import Data.List.NonEmpty        (head)
 import Data.Maybe                (fromJust)
 import Data.Ranged.Ranges        (Range (..), emptyRange,
                                  rangeIntersection)
@@ -47,24 +49,24 @@ import PostgREST.RangeQuery (NonnegRange, allRange, rangeGeq,
                             rangeLimit, rangeOffset, rangeRequested,
                             restrictRange)
 import PostgREST.Types
-import Protolude
+import Protolude            hiding (head, toS)
+import Protolude.Conv       (toS)

 type RequestBody = BL.ByteString

+data InvokeMethod = InvHead | InvGet | InvPost deriving Eq
 -- | Types of things a user wants to do to tables/views/procs
-data Action = ActionCreate  | ActionRead
-            | ActionUpdate  | ActionDelete
-            | ActionInfo    | ActionInvoke{isReadOnly :: Bool}
-            | ActionInspect | ActionSingleUpsert
+data Action = ActionCreate       | ActionRead{isHead :: Bool}
+            | ActionUpdate       | ActionDelete
+            | ActionSingleUpsert | ActionInvoke InvokeMethod
+            | ActionInfo         | ActionInspect{isHead :: Bool}
            deriving Eq
 -- | The target db object of a user action
 data Target = TargetIdent QualifiedIdentifier
            | TargetProc{tpQi :: QualifiedIdentifier, tpIsRootSpec :: Bool}
-            | TargetDefaultSpec -- The default spec offered at root "/"
+            | TargetDefaultSpec{tdsSchema :: Schema} -- The default spec offered at root "/"
            | TargetUnknown [Text]
            deriving Eq
-- | How to return the inserted data
-data PreferRepresentation = Full | HeadersOnly | None deriving Eq

 {-|
  Describes what the user wants to do. This data type is a
@@ -74,83 +76,85 @@ data PreferRepresentation = Full | HeadersOnly | None deriving Eq
  if it is an action we are able to perform.
 -}
 data ApiRequest = ApiRequest {
-  -- | Similar but not identical to HTTP verb, e.g. Create/Invoke both POST
-    iAction                      :: Action
-  -- | Requested range of rows within response
-  , iRange                       :: M.HashMap ByteString NonnegRange
-  -- | The target, be it calling a proc or accessing a table
-  , iTarget                      :: Target
-  -- | Content types the client will accept, [CTAny] if no Accept header
-  , iAccepts                     :: [ContentType]
-  -- | Data sent by client and used for mutation actions
-  , iPayload                     :: Maybe PayloadJSON
-  -- | If client wants created items echoed back
-  , iPreferRepresentation        :: PreferRepresentation
-  -- | Pass all parameters as a single json object to a stored procedure
-  , iPreferSingleObjectParameter :: Bool
-  -- | Whether the client wants a result count (slower)
-  , iPreferCount                 :: Bool
-  -- | Whether the client wants to UPSERT or ignore records on PK conflict
-  , iPreferResolution            :: Maybe PreferResolution
-  -- | Filters on the result ("id", "eq.10")
-  , iFilters                     :: [(Text, Text)]
-  -- | &and and &or parameters used for complex boolean logic
-  , iLogic                       :: [(Text, Text)]
-  -- | &select parameter used to shape the response
-  , iSelect                      :: Text
-  -- | &columns parameter used to shape the payload
-  , iColumns                     :: Maybe Text
-  -- | &order parameters for each level
-  , iOrder                       :: [(Text, Text)]
-  -- | Alphabetized (canonical) request query string for response URLs
-  , iCanonicalQS                 :: ByteString
-  -- | JSON Web Token
-  , iJWT                         :: Text
-  -- | HTTP request headers
-  , iHeaders                     :: [(Text, Text)]
-  -- | Request Cookies
-  , iCookies                     :: [(Text, Text)]
+    iAction               :: Action                           -- ^ Similar but not identical to HTTP verb, e.g. Create/Invoke both POST
+  , iRange                :: M.HashMap ByteString NonnegRange -- ^ Requested range of rows within response
+  , iTopLevelRange        :: NonnegRange                      -- ^ Requested range of rows from the top level
+  , iTarget               :: Target                           -- ^ The target, be it calling a proc or accessing a table
+  , iAccepts              :: [ContentType]                    -- ^ Content types the client will accept, [CTAny] if no Accept header
+  , iPayload              :: Maybe PayloadJSON                -- ^ Data sent by client and used for mutation actions
+  , iPreferRepresentation :: PreferRepresentation             -- ^ If client wants created items echoed back
+  , iPreferParameters     :: Maybe PreferParameters           -- ^ How to pass parameters to a stored procedure
+  , iPreferCount          :: Maybe PreferCount                -- ^ Whether the client wants a result count
+  , iPreferResolution     :: Maybe PreferResolution           -- ^ Whether the client wants to UPSERT or ignore records on PK conflict
+  , iFilters              :: [(Text, Text)]                   -- ^ Filters on the result ("id", "eq.10")
+  , iLogic                :: [(Text, Text)]                   -- ^ &and and &or parameters used for complex boolean logic
+  , iSelect               :: Maybe Text                       -- ^ &select parameter used to shape the response
+  , iOnConflict           :: Maybe Text                       -- ^ &on_conflict parameter used to upsert on specific unique keys
+  , iColumns              :: Maybe Text                       -- ^ &columns parameter used to shape the payload
+  , iOrder                :: [(Text, Text)]                   -- ^ &order parameters for each level
+  , iCanonicalQS          :: ByteString                       -- ^ Alphabetized (canonical) request query string for response URLs
+  , iJWT                  :: Text                             -- ^ JSON Web Token
+  , iHeaders              :: [(Text, Text)]                   -- ^ HTTP request headers
+  , iCookies              :: [(Text, Text)]                   -- ^ Request Cookies
+  , iPath                 :: ByteString                       -- ^ Raw request path
+  , iMethod               :: ByteString                       -- ^ Raw request method
+  , iProfile              :: Maybe Schema                     -- ^ The request profile for enabling use of multiple schemas. Follows the spec in hhttps://www.w3.org/TR/dx-prof-conneg/ttps://www.w3.org/TR/dx-prof-conneg/.
+  , iSchema               :: Schema                           -- ^ The request schema. Can vary depending on iProfile.
  }

 -- | Examines HTTP request and translates it into user intent.
-userApiRequest :: Schema -> Maybe QualifiedIdentifier -> Request -> RequestBody -> Either ApiRequestError ApiRequest
-userApiRequest schema rootSpec req reqBody
-  | isTargetingProc && method `notElem` ["GET", "POST"] = Left ActionInappropriate
+userApiRequest :: NonEmpty Schema -> Maybe Text -> Request -> RequestBody -> Either ApiRequestError ApiRequest
+userApiRequest confSchemas rootSpec req reqBody
+  | isJust profile && fromJust profile `notElem` confSchemas = Left $ UnacceptableSchema $ toList confSchemas
+  | isTargetingProc && method `notElem` ["HEAD", "GET", "POST"] = Left ActionInappropriate
  | topLevelRange == emptyRange = Left InvalidRange
  | shouldParsePayload && isLeft payload = either (Left . InvalidBody . toS) witness payload
  | otherwise = Right ApiRequest {
      iAction = action
      , iTarget = target
      , iRange = ranges
+      , iTopLevelRange = topLevelRange
      , iAccepts = maybe [CTAny] (map decodeContentType . parseHttpAccept) $ lookupHeader "accept"
      , iPayload = relevantPayload
      , iPreferRepresentation = representation
-      , iPreferSingleObjectParameter = singleObject
-      , iPreferCount = hasPrefer "count=exact"
-      , iPreferResolution = if hasPrefer (show MergeDuplicates) then Just MergeDuplicates
-                            else if hasPrefer (show IgnoreDuplicates) then Just IgnoreDuplicates
-                            else Nothing
+      , iPreferParameters = if | hasPrefer (show SingleObject)     -> Just SingleObject
+                               | hasPrefer (show MultipleObjects)  -> Just MultipleObjects
+                               | otherwise                         -> Nothing
+      , iPreferCount      = if | hasPrefer (show ExactCount)     -> Just ExactCount
+                               | hasPrefer (show PlannedCount)   -> Just PlannedCount
+                               | hasPrefer (show EstimatedCount) -> Just EstimatedCount
+                               | otherwise                         -> Nothing
+      , iPreferResolution = if | hasPrefer (show MergeDuplicates)  -> Just MergeDuplicates
+                               | hasPrefer (show IgnoreDuplicates) -> Just IgnoreDuplicates
+                               | otherwise                         -> Nothing
      , iFilters = filters
      , iLogic = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["and", "or"] k ]
-      , iSelect = toS $ fromMaybe "*" $ join $ lookup "select" qParams
+      , iSelect = toS <$> join (lookup "select" qParams)
+      , iOnConflict = toS <$> join (lookup "on_conflict" qParams)
      , iColumns = columns
      , iOrder = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["order"] k ]
      , iCanonicalQS = toS $ urlEncodeVars
        . L.sortOn fst
        . map (join (***) toS . second (fromMaybe BS.empty))
-        $ queryStringWPlus
+        $ qString
      , iJWT = tokenStr
-      , iHeaders = [ (toS $ CI.foldedCase k, toS v) | (k,v) <- hdrs, k /= hAuthorization, k /= hCookie]
+      , iHeaders = [ (toS $ CI.foldedCase k, toS v) | (k,v) <- hdrs, k /= hCookie]
      , iCookies = maybe [] parseCookiesText $ lookupHeader "Cookie"
+      , iPath = rawPathInfo req
+      , iMethod = method
+      , iProfile = profile
+      , iSchema = schema
      }
 where
-  -- queryString with '+' not converted to ' '
-  queryStringWPlus = parseQueryReplacePlus False $ rawQueryString req
+  -- queryString with '+' converted to ' '(space)
+  qString = parseQueryReplacePlus True $ rawQueryString req
  -- rpcQParams = Rpc query params e.g. /rpc/name?param1=val1, similar to filter but with no operator(eq, lt..)
  (filters, rpcQParams) =
    case action of
-      ActionInvoke{isReadOnly=True} -> partition (liftM2 (||) (isEmbedPath . fst) (hasOperator . snd)) flts
-      _ -> (flts, [])
+      ActionInvoke InvGet  -> partitionFlts
+      ActionInvoke InvHead -> partitionFlts
+      _                    -> (flts, [])
+  partitionFlts = partition (liftM2 (||) (isEmbedPath . fst) (hasOperator . snd)) flts
  flts =
    [ (toS k, toS $ fromJust v) |
      (k,v) <- qParams, isJust v,
@@ -163,13 +167,17 @@ userApiRequest schema rootSpec req reqBody
  isTargetingProc = case target of
    TargetProc _ _ -> True
    _              -> False
+  isTargetingDefaultSpec = case target of
+    TargetDefaultSpec _ -> True
+    _                   -> False
  contentType = decodeContentType . fromMaybe "application/json" $ lookupHeader "content-type"
-  columns | action `elem` [ActionCreate, ActionUpdate, ActionInvoke{isReadOnly=False}] = toS <$> join (lookup "columns" qParams)
-          | otherwise = Nothing
+  columns
+    | action `elem` [ActionCreate, ActionUpdate, ActionInvoke InvPost] = toS <$> join (lookup "columns" qParams)
+    | otherwise = Nothing
  payload =
    case (contentType, action) of
-      (_, ActionInvoke{isReadOnly=True}) ->
-        Right $ ProcessedJSON (JSON.encode $ M.fromList $ second JSON.toJSON <$> rpcQParams) PJObject (S.fromList $ fst <$> rpcQParams)
+      (_, ActionInvoke InvGet)  -> Right rpcPrmsToJson
+      (_, ActionInvoke InvHead) -> Right rpcPrmsToJson
      (CTApplicationJSON, _) ->
        if isJust columns
          then Right $ RawJSON reqBody
@@ -183,50 +191,75 @@ userApiRequest schema rootSpec req reqBody
      (CTOther "application/x-www-form-urlencoded", _) ->
        let json = M.fromList . map (toS *** JSON.String . toS) . parseSimpleQuery $ toS reqBody
            keys = S.fromList $ M.keys json in
-        Right $ ProcessedJSON (JSON.encode json) PJObject keys
+        Right $ ProcessedJSON (JSON.encode json) keys
      (ct, _) ->
        Left $ toS $ "Content-Type not acceptable: " <> toMime ct
-  topLevelRange = fromMaybe allRange $ M.lookup "limit" ranges
+  rpcPrmsToJson = ProcessedJSON (JSON.encode $ M.fromList $ second JSON.toJSON <$> rpcQParams) (S.fromList $ fst <$> rpcQParams)
+  topLevelRange = fromMaybe allRange $ M.lookup "limit" ranges -- if no limit is specified, get all the request rows
  action =
    case method of
-      "GET"      | target == TargetDefaultSpec -> ActionInspect
-                 | isTargetingProc -> ActionInvoke{isReadOnly=True}
-                 | otherwise -> ActionRead
-
+      -- The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response
+      -- From https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.4
+      "HEAD"     | isTargetingDefaultSpec -> ActionInspect{isHead=True}
+                 | isTargetingProc        -> ActionInvoke InvHead
+                 | otherwise              -> ActionRead{isHead=True}
+      "GET"      | isTargetingDefaultSpec -> ActionInspect{isHead=False}
+                 | isTargetingProc        -> ActionInvoke InvGet
+                 | otherwise              -> ActionRead{isHead=False}
      "POST"    -> if isTargetingProc
-                    then ActionInvoke{isReadOnly=False}
+                    then ActionInvoke InvPost
                    else ActionCreate
      "PATCH"   -> ActionUpdate
      "PUT"     -> ActionSingleUpsert
      "DELETE"  -> ActionDelete
      "OPTIONS" -> ActionInfo
-      _         -> ActionInspect
+      _         -> ActionInspect{isHead=False}
+
+  defaultSchema = head confSchemas
+  profile
+    | length confSchemas <= 1 -- only enable content negotiation by profile when there are multiple schemas specified in the config
+      = Nothing
+    | action `elem` [ActionCreate, ActionUpdate, ActionSingleUpsert, ActionDelete, ActionInvoke InvPost] -- POST/PATCH/PUT/DELETE don't use the same header as per the spec
+      = Just $ maybe defaultSchema toS $ lookupHeader "Content-Profile"
+    | action `elem` [ActionRead True, ActionRead False, ActionInvoke InvGet, ActionInvoke InvHead,
+                     ActionInspect False, ActionInspect True, ActionInfo]
+      = Just $ maybe defaultSchema toS $ lookupHeader "Accept-Profile"
+    | otherwise = Nothing
+  schema = fromMaybe defaultSchema profile
  target = case path of
    []            -> case rootSpec of
-                       Just rsQi -> TargetProc rsQi True
-                       Nothing   -> TargetDefaultSpec
+                       Just pName -> TargetProc (QualifiedIdentifier schema pName) True
+                       Nothing    -> TargetDefaultSpec schema
    [table]       -> TargetIdent $ QualifiedIdentifier schema table
    ["rpc", proc] -> TargetProc (QualifiedIdentifier schema proc) False
    other         -> TargetUnknown other

-  shouldParsePayload = action `elem` [ActionCreate, ActionUpdate, ActionSingleUpsert, ActionInvoke{isReadOnly=False}, ActionInvoke{isReadOnly=True}]
+  shouldParsePayload =
+    action `elem`
+    [ActionCreate, ActionUpdate, ActionSingleUpsert,
+    ActionInvoke InvPost,
+    -- Though ActionInvoke{isGet=True}(a GET /rpc/..) doesn't really have a payload, we use the payload variable as a way
+    -- to store the query string arguments to the function.
+    ActionInvoke InvGet,
+    ActionInvoke InvHead]
  relevantPayload | shouldParsePayload = rightToMaybe payload
                  | otherwise = Nothing
  path            = pathInfo req
  method          = requestMethod req
  hdrs            = requestHeaders req
-  qParams         = [(toS k, v)|(k,v) <- queryStringWPlus]
+  qParams         = [(toS k, v)|(k,v) <- qString]
  lookupHeader    = flip lookup hdrs
  hasPrefer :: Text -> Bool
  hasPrefer val   = any (\(h,v) -> h == "Prefer" && val `elem` split v) hdrs
    where
        split :: BS.ByteString -> [Text]
        split = map T.strip . T.split (==',') . toS
-  singleObject    = hasPrefer "params=single-object"
  representation
-    | hasPrefer "return=representation" = Full
-    | hasPrefer "return=minimal" = None
-    | otherwise = HeadersOnly
+    | hasPrefer (show Full) = Full
+    | hasPrefer (show None) = None
+    | otherwise             = if action == ActionCreate
+                                then HeadersOnly -- Assume the user wants the Location header(for POST) by default
+                                else None
  auth = fromMaybe "" $ lookupHeader hAuthorization
  tokenStr = case T.split (== ' ') (toS auth) of
    ("Bearer" : t : _) -> t
@@ -300,14 +333,14 @@ payloadAttributes raw json =
                JSON.Object x -> S.fromList (M.keys x) == canonicalKeys
                _ -> False) arr in
          if areKeysUniform
-            then Just $ ProcessedJSON raw (PJArray $ V.length arr) canonicalKeys
+            then Just $ ProcessedJSON raw canonicalKeys
            else Nothing
        Just _ -> Nothing
        Nothing -> Just emptyPJArray

-    JSON.Object o -> Just $ ProcessedJSON raw PJObject (S.fromList $ M.keys o)
+    JSON.Object o -> Just $ ProcessedJSON raw (S.fromList $ M.keys o)

    -- truncate everything else to an empty array.
    _ -> Just emptyPJArray
  where
-    emptyPJArray = ProcessedJSON (JSON.encode emptyArray) (PJArray 0) S.empty
+    emptyPJArray = ProcessedJSON (JSON.encode emptyArray) S.empty
@@ -1,4 +1,16 @@
+{-|
+Module      : PostgREST.App
+Description : PostgREST main application
+
+This module is in charge of mapping HTTP requests to PostgreSQL queries.
+Some of its functionality includes:
+
+- Mapping HTTP request methods to proper SQL statements. For example, a GET request is translated to executing a SELECT query in a read-only TRANSACTION.
+- Producing HTTP Headers according to RFCs.
+- Content Negotiation
+-}
 {-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE MultiWayIf          #-}
 {-# LANGUAGE NamedFieldPuns      #-}
 {-# LANGUAGE ScopedTypeVariables #-}

@@ -8,13 +20,13 @@ module PostgREST.App (

 import qualified Data.ByteString.Char8      as BS
 import qualified Data.HashMap.Strict        as M
+import qualified Data.List                  as L (union)
 import qualified Data.Set                   as S
 import qualified Hasql.Pool                 as P
 import qualified Hasql.Transaction          as H
 import qualified Hasql.Transaction          as HT
 import qualified Hasql.Transaction.Sessions as HT

-import Data.Aeson                           as JSON
 import Data.Function                        (id)
 import Data.IORef                           (IORef, readIORef)
 import Data.Time.Clock                      (UTCTime)
@@ -28,35 +40,37 @@ import Network.HTTP.Types.Status
 import Network.Wai

 import PostgREST.ApiRequest       (Action (..), ApiRequest (..),
-                                   ContentType (..),
-                                   PreferRepresentation (..),
-                                   Target (..), mutuallyAgreeable,
-                                   userApiRequest)
+                                   InvokeMethod (..), Target (..),
+                                   mutuallyAgreeable, userApiRequest)
 import PostgREST.Auth             (containsRole, jwtClaims,
                                   parseSecret)
 import PostgREST.Config           (AppConfig (..))
-import PostgREST.DbRequestBuilder (fieldNames, mutateRequest,
-                                   readRequest)
+import PostgREST.DbRequestBuilder (mutateRequest, readRequest,
+                                   returningCols)
 import PostgREST.DbStructure
 import PostgREST.Error            (PgError (..), SimpleError (..),
                                   errorResponseFor, singularityError)
 import PostgREST.Middleware
 import PostgREST.OpenAPI
 import PostgREST.Parsers          (pRequestColumns)
-import PostgREST.QueryBuilder     (ResultsWithCount, callProc,
+import PostgREST.QueryBuilder     (limitedQuery, mutateRequestToQuery,
+                                   readRequestToCountQuery,
+                                   readRequestToQuery,
+                                   requestToCallProcQuery)
+import PostgREST.RangeQuery       (allRange, contentRangeH,
+                                   rangeStatusHeader)
+import PostgREST.Statements       (callProcStatement,
+                                   createExplainStatement,
                                   createReadStatement,
-                                   createWriteStatement,
-                                   requestToCountQuery,
-                                   requestToQuery)
-import PostgREST.RangeQuery       (allRange, rangeOffset)
+                                   createWriteStatement)
 import PostgREST.Types
-import Protolude                  hiding (Proxy, intercalate)
+import Protolude                  hiding (Proxy, intercalate, toS)
+import Protolude.Conv             (toS)

 postgrest :: AppConfig -> IORef (Maybe DbStructure) -> P.Pool -> IO UTCTime -> IO () -> Application
 postgrest conf refDbStructure pool getTime worker =
  let middle = (if configQuiet conf then id else logStdout) . defaultMiddle
      jwtSecret = parseSecret <$> configJwtSecret conf in
-
  middle $ \ req respond -> do
    time <- getTime
    body <- strictRequestBody req
@@ -65,8 +79,9 @@ postgrest conf refDbStructure pool getTime worker =
      Nothing -> respond . errorResponseFor $ ConnectionLostError
      Just dbStructure -> do
        response <- do
-          -- Need to parse ?columns early because findProc needs it to solve overloaded functions
-          let apiReq = userApiRequest (configSchema conf) (configRootSpec conf) req body
+          -- Need to parse ?columns early because findProc needs it to solve overloaded functions.
+          -- TODO: move this logic to the app function
+          let apiReq = userApiRequest (configSchemas conf) (configRootSpec conf) req body
              apiReqCols = (,) <$> apiReq <*> (pRequestColumns =<< iColumns <$> apiReq)
          case apiReqCols of
            Left err -> return . errorResponseFor $ err
@@ -78,7 +93,7 @@ postgrest conf refDbStructure pool getTime worker =
                    (Just RawJSON{}, Just cls)      -> cls
                    _                               -> S.empty
                  proc = case iTarget apiRequest of
-                    TargetProc qi _ -> findProc qi cols (iPreferSingleObjectParameter apiRequest) $ dbProcs dbStructure
+                    TargetProc qi _ -> findProc qi cols (iPreferParameters apiRequest == Just SingleObject) $ dbProcs dbStructure
                    _ -> Nothing
                  handleReq = runWithClaims conf eClaims (app dbStructure proc cols conf) apiRequest
                  txMode = transactionMode proc (iAction apiRequest)
@@ -90,46 +105,57 @@ postgrest conf refDbStructure pool getTime worker =
 transactionMode :: Maybe ProcDescription -> Action -> HT.Mode
 transactionMode proc action =
  case action of
-    ActionRead -> HT.Read
-    ActionInfo -> HT.Read
-    ActionInspect -> HT.Read
-    ActionInvoke{isReadOnly=False} ->
+    ActionRead _         -> HT.Read
+    ActionInfo           -> HT.Read
+    ActionInspect _      -> HT.Read
+    ActionInvoke InvGet  -> HT.Read
+    ActionInvoke InvHead -> HT.Read
+    ActionInvoke InvPost ->
      let v = maybe Volatile pdVolatility proc in
      if v == Stable || v == Immutable
         then HT.Read
         else HT.Write
-    ActionInvoke{isReadOnly=True} -> HT.Read
    _ -> HT.Write

 app :: DbStructure -> Maybe ProcDescription -> S.Set FieldName -> AppConfig -> ApiRequest -> H.Transaction Response
 app dbStructure proc cols conf apiRequest =
-  case responseContentTypeOrError (iAccepts apiRequest) (iAction apiRequest) (iTarget apiRequest) of
+  let rawContentTypes = (decodeContentType <$> configRawMediaTypes conf) `L.union` [ CTOctetStream, CTTextPlain ] in
+  case responseContentTypeOrError (iAccepts apiRequest) rawContentTypes (iAction apiRequest) (iTarget apiRequest) of
    Left errorResponse -> return errorResponse
    Right contentType ->
      case (iAction apiRequest, iTarget apiRequest, iPayload apiRequest) of

-        (ActionRead, TargetIdent qi, Nothing) ->
-          let partsField = (,) <$> readSqlParts
-                <*> (binaryField contentType =<< fldNames) in
-          case partsField of
+        (ActionRead headersOnly, TargetIdent (QualifiedIdentifier tSchema tName), Nothing) ->
+          case readSqlParts tSchema tName of
            Left errorResponse -> return errorResponse
-            Right ((q, cq), bField) -> do
-              let stm = createReadStatement q cq (contentType == CTSingularJSON) shouldCount
-                                            (contentType == CTTextCSV) bField
+            Right (q, cq, bField, _) -> do
+              let cQuery = if estimatedCount
+                             then limitedQuery cq ((+ 1) <$> maxRows) -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
+                             else cq
+                  stm = createReadStatement q cQuery (contentType == CTSingularJSON) shouldCount
+                        (contentType == CTTextCSV) bField pgVer
+                  explStm = createExplainStatement cq
              row <- H.statement () stm
-              let (tableTotal, queryTotal, _ , body) = row
-                  (status, contentRange) = rangeHeader queryTotal tableTotal
-                  canonical = iCanonicalQS apiRequest
-              return $
-                if contentType == CTSingularJSON && queryTotal /= 1
-                  then errorResponseFor . singularityError $ queryTotal
-                  else responseLBS status
-                    [toHeader contentType, contentRange,
-                      ("Content-Location",
-                        "/" <> toS (qiName qi) <>
-                          if BS.null canonical then "" else "?" <> toS canonical
-                      )
-                    ] (toS body)
+              let (tableTotal, queryTotal, _ , body, gucHeaders) = row
+              case gucHeaders of
+                Left _ -> return . errorResponseFor $ GucHeadersError
+                Right ghdrs -> do
+                  total <- if | plannedCount   -> H.statement () explStm
+                              | estimatedCount -> if tableTotal > (fromIntegral <$> maxRows)
+                                                    then do estTotal <- H.statement () explStm
+                                                            pure $ if estTotal > tableTotal then estTotal else tableTotal
+                                                    else pure tableTotal
+                              | otherwise      -> pure tableTotal
+                  let (status, contentRange) = rangeStatusHeader topLevelRange queryTotal total
+                      headers = addHeadersIfNotIncluded (catMaybes [
+                                  Just $ toHeader contentType, Just contentRange,
+                                  Just $ contentLocationH tName (iCanonicalQS apiRequest), profileH])
+                                (unwrapGucHeader <$> ghdrs)
+                      rBody = if headersOnly then mempty else toS body
+                  return $
+                    if contentType == CTSingularJSON && queryTotal /= 1
+                      then errorResponseFor . singularityError $ queryTotal
+                      else responseLBS status headers rBody

        (ActionCreate, TargetIdent (QualifiedIdentifier tSchema tName), Just pJson) ->
          case mutateSqlParts tSchema tName of
@@ -138,32 +164,31 @@ app dbStructure proc cols conf apiRequest =
              let pkCols = tablePKCols dbStructure tSchema tName
                  stm = createWriteStatement sq mq
                    (contentType == CTSingularJSON) True
-                    (contentType == CTTextCSV) (iPreferRepresentation apiRequest) pkCols
+                    (contentType == CTTextCSV) (iPreferRepresentation apiRequest) pkCols pgVer
              row <- H.statement (toS $ pjRaw pJson) stm
-              let (_, queryTotal, fs, body) = extractQueryResult row
-                  headers = catMaybes [
-                      if null fs
-                        then Nothing
-                        else Just (hLocation, "/" <> toS tName <> renderLocationFields fs)
-                    , if iPreferRepresentation apiRequest == Full
-                        then Just $ toHeader contentType
-                        else Nothing
-                    , Just $ contentRangeH 1 0 $
-                        if shouldCount then Just queryTotal else Nothing
-                    , if null pkCols
-                        then Nothing
-                        else (\x -> ("Preference-Applied", show x)) <$> iPreferResolution apiRequest
-                    ]
-              if contentType == CTSingularJSON
-                 && queryTotal /= 1
-                 && iPreferRepresentation apiRequest == Full
-                then do
-                  HT.condemn
-                  return . errorResponseFor . singularityError $ queryTotal
-              else
-                return . responseLBS status201 headers $
-                  if iPreferRepresentation apiRequest == Full
-                    then toS body else ""
+              let (_, queryTotal, fields, body, gucHeaders) = row
+              case gucHeaders of
+                Left _ -> return . errorResponseFor $ GucHeadersError
+                Right ghdrs -> do
+                  let
+                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
+                                          then ([Just $ toHeader contentType, profileH], toS body)
+                                          else ([], mempty)
+                    headers = addHeadersIfNotIncluded (catMaybes ([
+                          if null fields
+                            then Nothing
+                            else Just $ locationH tName fields
+                        , Just $ contentRangeH 1 0 $ if shouldCount then Just queryTotal else Nothing
+                        , if null pkCols && isNothing (iOnConflict apiRequest)
+                            then Nothing
+                            else (\x -> ("Preference-Applied", encodeUtf8 (show x))) <$> iPreferResolution apiRequest
+                        ] ++ ctHeaders)) (unwrapGucHeader <$> ghdrs)
+                  if contentType == CTSingularJSON && queryTotal /= 1
+                    then do
+                      HT.condemn
+                      return . errorResponseFor . singularityError $ queryTotal
+                    else
+                      return $ responseLBS status201 headers rBody

        (ActionUpdate, TargetIdent (QualifiedIdentifier tSchema tName), Just pJson) ->
          case mutateSqlParts tSchema tName of
@@ -171,62 +196,54 @@ app dbStructure proc cols conf apiRequest =
            Right (sq, mq) -> do
              let stm = createWriteStatement sq mq
                    (contentType == CTSingularJSON) False (contentType == CTTextCSV)
-                    (iPreferRepresentation apiRequest) []
+                    (iPreferRepresentation apiRequest) [] pgVer
              row <- H.statement (toS $ pjRaw pJson) stm
-              let (_, queryTotal, _, body) = extractQueryResult row
+              let (_, queryTotal, _, body, gucHeaders) = row
+              case gucHeaders of
+                Left _ -> return . errorResponseFor $ GucHeadersError
+                Right ghdrs -> do
+                  let
+                    updateIsNoOp = S.null cols
+                    status | queryTotal == 0 && not updateIsNoOp      = status404
+                           | iPreferRepresentation apiRequest == Full = status200
+                           | otherwise                                = status204
+                    contentRangeHeader = contentRangeH 0 (queryTotal - 1) $ if shouldCount then Just queryTotal else Nothing
+                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
+                                          then ([Just $ toHeader contentType, profileH], toS body)
+                                          else ([], mempty)
+                    headers = addHeadersIfNotIncluded (catMaybes ctHeaders ++ [contentRangeHeader]) (unwrapGucHeader <$> ghdrs)
+                  if contentType == CTSingularJSON && queryTotal /= 1
+                    then do
+                      HT.condemn
+                      return . errorResponseFor . singularityError $ queryTotal
+                    else
+                      return $ responseLBS status headers rBody

-                  updateIsNoOp       = S.null cols
-                  contentRangeHeader = contentRangeH 0 (queryTotal - 1) $
-                                          if shouldCount then Just queryTotal else Nothing
-                  minimalHeaders     = [contentRangeHeader]
-                  fullHeaders        = toHeader contentType : minimalHeaders
-
-                  status | queryTotal == 0 && not updateIsNoOp      = status404
-                         | iPreferRepresentation apiRequest == Full = status200
-                         | otherwise                                = status204
-
-              case (contentType, iPreferRepresentation apiRequest) of
-                (CTSingularJSON, Full)
-                      | queryTotal == 1 -> return $ responseLBS status fullHeaders (toS body)
-                      | otherwise       -> HT.condemn >> (return . errorResponseFor . singularityError) queryTotal
-
-                (_, Full) ->
-                  return $ responseLBS status fullHeaders (toS body)
-
-                (_, _) ->
-                  return $ responseLBS status minimalHeaders mempty
-
-
-        (ActionSingleUpsert, TargetIdent (QualifiedIdentifier tSchema tName), Just ProcessedJSON{pjRaw, pjType, pjKeys}) ->
+        (ActionSingleUpsert, TargetIdent (QualifiedIdentifier tSchema tName), Just pJson) ->
          case mutateSqlParts tSchema tName of
            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              let isSingle = case pjType of
-                               PJArray len -> len == 1
-                               PJObject    -> True
-                  colNames = colName <$> tableCols dbStructure tSchema tName
+            Right (sq, mq) ->
              if topLevelRange /= allRange
                then return . errorResponseFor $ PutRangeNotAllowedError
-              else if not isSingle
-                then return . errorResponseFor $ PutSingletonError
-              else if S.fromList colNames /= pjKeys
-                then return . errorResponseFor $ PutPayloadIncompleteError
              else do
-                row <- H.statement (toS pjRaw) $
+                row <- H.statement (toS $ pjRaw pJson) $
                       createWriteStatement sq mq (contentType == CTSingularJSON) False
-                                            (contentType == CTTextCSV) (iPreferRepresentation apiRequest) []
-                let (_, queryTotal, _, body) = extractQueryResult row
-                -- Makes sure the querystring pk matches the payload pk
-                -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted, PUT /items?id=eq.14 { "id" : 2, .. } is rejected
-                -- If this condition is not satisfied then nothing is inserted, check the WHERE for INSERT in QueryBuilder.hs to see how it's done
-                if queryTotal /= 1
-                  then do
-                    HT.condemn
-                    return . errorResponseFor $ PutMatchingPkError
-                  else
-                    return $ if iPreferRepresentation apiRequest == Full
-                      then responseLBS status200 [toHeader contentType] (toS body)
-                      else responseLBS status204 [] ""
+                                            (contentType == CTTextCSV) (iPreferRepresentation apiRequest) [] pgVer
+                let (_, queryTotal, _, body, gucHeaders) = row
+                case gucHeaders of
+                  Left _ -> return . errorResponseFor $ GucHeadersError
+                  Right ghdrs -> do
+                    let headers = addHeadersIfNotIncluded (catMaybes [Just $ toHeader contentType, profileH]) (unwrapGucHeader <$> ghdrs)
+                        (status, rBody) = if iPreferRepresentation apiRequest == Full then (status200, toS body) else (status204, mempty)
+                    -- Makes sure the querystring pk matches the payload pk
+                    -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted, PUT /items?id=eq.14 { "id" : 2, .. } is rejected
+                    -- If this condition is not satisfied then nothing is inserted, check the WHERE for INSERT in QueryBuilder.hs to see how it's done
+                    if queryTotal /= 1
+                      then do
+                        HT.condemn
+                        return . errorResponseFor $ PutMatchingPkError
+                      else
+                        return $ responseLBS status headers rBody

        (ActionDelete, TargetIdent (QualifiedIdentifier tSchema tName), Nothing) ->
          case mutateSqlParts tSchema tName of
@@ -235,65 +252,68 @@ app dbStructure proc cols conf apiRequest =
              let stm = createWriteStatement sq mq
                    (contentType == CTSingularJSON) False
                    (contentType == CTTextCSV)
-                    (iPreferRepresentation apiRequest) []
+                    (iPreferRepresentation apiRequest) [] pgVer
              row <- H.statement mempty stm
-              let (_, queryTotal, _, body) = extractQueryResult row
-                  r = contentRangeH 1 0 $
-                        if shouldCount then Just queryTotal else Nothing
-              if contentType == CTSingularJSON
-                 && queryTotal /= 1
-                 && iPreferRepresentation apiRequest == Full
-                then do
-                  HT.condemn
-                  return . errorResponseFor . singularityError $ queryTotal
-                else
-                  return $ if iPreferRepresentation apiRequest == Full
-                    then responseLBS status200 [toHeader contentType, r] (toS body)
-                    else responseLBS status204 [r] ""
+              let (_, queryTotal, _, body, gucHeaders) = row
+              case gucHeaders of
+                Left _ -> return . errorResponseFor $ GucHeadersError
+                Right ghdrs -> do
+                  let
+                    status = if iPreferRepresentation apiRequest == Full then status200 else status204
+                    contentRangeHeader = contentRangeH 1 0 $ if shouldCount then Just queryTotal else Nothing
+                    (ctHeaders, rBody) = if iPreferRepresentation apiRequest == Full
+                                          then ([Just $ toHeader contentType, profileH], toS body)
+                                          else ([], mempty)
+                    headers = addHeadersIfNotIncluded (catMaybes ctHeaders ++ [contentRangeHeader]) (unwrapGucHeader <$> ghdrs)
+                  if contentType == CTSingularJSON
+                     && queryTotal /= 1
+                    then do
+                      HT.condemn
+                      return . errorResponseFor . singularityError $ queryTotal
+                    else
+                      return $ responseLBS status headers rBody

        (ActionInfo, TargetIdent (QualifiedIdentifier tSchema tTable), Nothing) ->
          let mTable = find (\t -> tableName t == tTable && tableSchema t == tSchema) (dbTables dbStructure) in
          case mTable of
            Nothing -> return notFound
            Just table ->
-              let acceptH = (hAllow, if tableInsertable table then "GET,POST,PATCH,DELETE" else "GET") in
-              return $ responseLBS status200 [allOrigins, acceptH] ""
+              let allowH = (hAllow, if tableInsertable table then "GET,POST,PATCH,DELETE" else "GET")
+                  allOrigins = ("Access-Control-Allow-Origin", "*") :: Header in
+              return $ responseLBS status200 [allOrigins, allowH] mempty

-        (ActionInvoke _, TargetProc qi _, Just pJson) ->
-          let returnsScalar = case proc of
-                Just ProcDescription{pdReturnType = (Single (Scalar _))} -> True
-                _ -> False
-              rpcBinaryField = if returnsScalar
-                                 then Right Nothing
-                                 else binaryField contentType =<< fldNames
-              parts = (,) <$> readSqlParts <*> rpcBinaryField in
-          case parts of
+        (ActionInvoke invMethod, TargetProc qi@(QualifiedIdentifier tSchema pName) _, Just pJson) ->
+          let tName = fromMaybe pName $ procTableName =<< proc in
+          case readSqlParts tSchema tName of
            Left errorResponse -> return errorResponse
-            Right ((q, cq), bField) -> do
-              let singular = contentType == CTSingularJSON
-              row <- H.statement (toS $ pjRaw pJson) $
-                callProc qi (specifiedProcArgs cols proc) returnsScalar q cq shouldCount
-                         singular (iPreferSingleObjectParameter apiRequest)
-                         (contentType == CTTextCSV)
-                         (contentType `elem` rawContentTypes) bField
-                         (pgVersion dbStructure)
-              let (tableTotal, queryTotal, body, jsonHeaders) =
-                    fromMaybe (Just 0, 0, "[]", "[]") row
-                  (status, contentRange) = rangeHeader queryTotal tableTotal
-                  decodedHeaders = first toS $ JSON.eitherDecode $ toS jsonHeaders :: Either Text [GucHeader]
-              case decodedHeaders of
+            Right (q, cq, bField, returning) -> do
+              let
+                preferParams = iPreferParameters apiRequest
+                pq = requestToCallProcQuery qi (specifiedProcArgs cols proc) returnsScalar preferParams returning
+                stm = callProcStatement returnsScalar pq q cq shouldCount (contentType == CTSingularJSON)
+                        (contentType == CTTextCSV) (contentType `elem` rawContentTypes) (preferParams == Just MultipleObjects)
+                        bField pgVer
+              row <- H.statement (toS $ pjRaw pJson) stm
+              let (tableTotal, queryTotal, body, gucHeaders) = row
+              case gucHeaders of
                Left _ -> return . errorResponseFor $ GucHeadersError
-                Right hs ->
-                  if singular && queryTotal /= 1
+                Right ghdrs -> do
+                  let (status, contentRange) = rangeStatusHeader topLevelRange queryTotal tableTotal
+                      headers = addHeadersIfNotIncluded
+                        (catMaybes [Just $ toHeader contentType, Just contentRange, profileH])
+                        (unwrapGucHeader <$> ghdrs)
+                      rBody = if invMethod == InvHead then mempty else toS body
+                  if contentType == CTSingularJSON && queryTotal /= 1
                    then do
                      HT.condemn
                      return . errorResponseFor . singularityError $ queryTotal
-                    else return $ responseLBS status ([toHeader contentType, contentRange] ++ toHeaders hs) (toS body)
+                    else
+                      return $ responseLBS status headers rBody

-        (ActionInspect, TargetDefaultSpec, Nothing) -> do
+        (ActionInspect headersOnly, TargetDefaultSpec tSchema, Nothing) -> do
          let host = configHost conf
              port = toInteger $ configPort conf
-              proxy = pickProxy $ toS <$> configProxyUri conf
+              proxy = pickProxy $ toS <$> configOpenAPIProxyUri conf
              uri Nothing = ("http", host, port, "/")
              uri (Just Proxy { proxyScheme = s, proxyHost = h, proxyPort = p, proxyPath = b }) = (s, h, p, b)
              uri' = uri proxy
@@ -301,46 +321,60 @@ app dbStructure proc cols conf apiRequest =
              toTableInfo = map (\t -> let (s, tn) = (tableSchema t, tableName t) in (t, tableCols dbStructure s tn, tablePKCols dbStructure s tn))
              encodeApi ti sd procs = encodeOpenAPI (concat $ M.elems procs) (toTableInfo ti) uri' sd $ dbPrimaryKeys dbStructure

-          body <- encodeApi <$> H.statement schema accessibleTables <*> H.statement schema schemaDescription <*> H.statement schema accessibleProcs
-          return $ responseLBS status200 [toHeader CTOpenAPI] $ toS body
+          body <- encodeApi <$>
+            H.statement tSchema accessibleTables <*>
+            H.statement tSchema schemaDescription <*>
+            H.statement tSchema accessibleProcs
+          return $ responseLBS status200 (catMaybes [Just $ toHeader CTOpenAPI, profileH]) (if headersOnly then mempty else toS body)

        _ -> return notFound

-    where
-      notFound = responseLBS status404 [] ""
-      allOrigins = ("Access-Control-Allow-Origin", "*") :: Header
-      shouldCount = iPreferCount apiRequest
-      schema = toS $ configSchema conf
-      topLevelRange = fromMaybe allRange $ M.lookup "limit" $ iRange apiRequest
-      rangeHeader queryTotal tableTotal =
-        let lower = rangeOffset topLevelRange
-            upper = lower + toInteger queryTotal - 1
-            contentRange = contentRangeH lower upper (toInteger <$> tableTotal)
-            status = rangeStatus lower upper (toInteger <$> tableTotal)
-        in (status, contentRange)
+      where
+        notFound = responseLBS status404 [] ""
+        maxRows = configMaxRows conf
+        exactCount = iPreferCount apiRequest == Just ExactCount
+        estimatedCount = iPreferCount apiRequest == Just EstimatedCount
+        plannedCount = iPreferCount apiRequest == Just PlannedCount
+        shouldCount = exactCount || estimatedCount
+        topLevelRange = iTopLevelRange apiRequest
+        returnsScalar = maybe False procReturnsScalar proc
+        pgVer = pgVersion dbStructure
+        profileH = contentProfileH <$> iProfile apiRequest

-      readReq = readRequest (configMaxRows conf) (dbRelations dbStructure) proc apiRequest
-      fldNames = fieldNames <$> readReq
-      readDbRequest = DbRead <$> readReq
-      selectQuery = requestToQuery schema False <$> readDbRequest
-      countQuery = requestToCountQuery schema <$> readDbRequest
-      readSqlParts = (,) <$> selectQuery <*> countQuery
-      mutationDbRequest s t = mutateRequest apiRequest t cols (tablePKCols dbStructure s t) =<< fldNames
-      mutateSqlParts s t =
-        (,) <$> selectQuery
-            <*> (requestToQuery schema False . DbMutate <$> mutationDbRequest s t)
+        readSqlParts s t =
+          let
+            readReq = readRequest s t maxRows (dbRelations dbStructure) apiRequest
+            returnings :: ReadRequest -> Either Response [FieldName]
+            returnings rr = Right (returningCols rr)
+          in
+          (,,,) <$>
+          (readRequestToQuery <$> readReq) <*>
+          (readRequestToCountQuery <$> readReq) <*>
+          (binaryField contentType rawContentTypes returnsScalar =<< readReq) <*>
+          (returnings =<< readReq)

-responseContentTypeOrError :: [ContentType] -> Action -> Target -> Either Response ContentType
-responseContentTypeOrError accepts action target = serves contentTypesForRequest accepts
+        mutateSqlParts s t =
+          let
+            readReq = readRequest s t maxRows (dbRelations dbStructure) apiRequest
+            mutReq = mutateRequest s t apiRequest cols (tablePKCols dbStructure s t) =<< readReq
+          in
+          (,) <$>
+          (readRequestToQuery <$> readReq) <*>
+          (mutateRequestToQuery <$> mutReq)
+
+responseContentTypeOrError :: [ContentType] -> [ContentType] -> Action -> Target -> Either Response ContentType
+responseContentTypeOrError accepts rawContentTypes action target = serves contentTypesForRequest accepts
  where
    contentTypesForRequest = case action of
-      ActionRead         ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV] ++ rawContentTypes
+      ActionRead _       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
+                             ++ rawContentTypes
      ActionCreate       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
      ActionUpdate       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
      ActionDelete       ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-      ActionInvoke _     ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV] ++ rawContentTypes ++
-                             [CTOpenAPI | tpIsRootSpec target]
-      ActionInspect      ->  [CTOpenAPI, CTApplicationJSON]
+      ActionInvoke _     ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
+                             ++ rawContentTypes
+                             ++ [CTOpenAPI | tpIsRootSpec target]
+      ActionInspect _    ->  [CTOpenAPI, CTApplicationJSON]
      ActionInfo         ->  [CTTextCSV]
      ActionSingleUpsert ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
    serves sProduces cAccepts =
@@ -352,41 +386,34 @@ responseContentTypeOrError accepts action target = serves contentTypesForRequest
  | If raw(binary) output is requested, check that ContentType is one of the admitted rawContentTypes and that
  | `?select=...` contains only one field other than `*`
 -}
-binaryField :: ContentType -> [FieldName] -> Either Response (Maybe FieldName)
-binaryField ct fldNames
+binaryField :: ContentType -> [ContentType] -> Bool -> ReadRequest -> Either Response (Maybe FieldName)
+binaryField ct rawContentTypes isScalarProc readReq
+  | isScalarProc = Right Nothing
  | ct `elem` rawContentTypes =
      let fieldName = headMay fldNames in
      if length fldNames == 1 && fieldName /= Just "*"
        then Right fieldName
        else Left . errorResponseFor $ BinaryFieldError ct
  | otherwise = Right Nothing
+  where
+    fldNames = fstFieldNames readReq

-splitKeyValue :: BS.ByteString -> (BS.ByteString, BS.ByteString)
-splitKeyValue kv = (k, BS.tail v)
-  where (k, v) = BS.break (== '=') kv
+locationH :: TableName -> [BS.ByteString] -> Header
+locationH tName fields =
+  let
+    locationFields = renderSimpleQuery True $ splitKeyValue <$> fields
+  in
+    (hLocation, "/" <> toS tName <> locationFields)
+  where
+    splitKeyValue :: BS.ByteString -> (BS.ByteString, BS.ByteString)
+    splitKeyValue kv =
+      let (k, v) = BS.break (== '=') kv
+      in (k, BS.tail v)

-renderLocationFields :: [BS.ByteString] -> BS.ByteString
-renderLocationFields fields =
-  renderSimpleQuery True $ map splitKeyValue fields
+contentLocationH :: TableName -> ByteString -> Header
+contentLocationH tName qString =
+  ("Content-Location", "/" <> toS tName <> if BS.null qString then mempty else "?" <> toS qString)

-rangeStatus :: Integer -> Integer -> Maybe Integer -> Status
-rangeStatus _ _ Nothing = status200
-rangeStatus lower upper (Just total)
-  | lower > total            = status416
-  | (1 + upper - lower) < total = status206
-  | otherwise               = status200
-
-contentRangeH :: (Integral a, Show a) => a -> a -> Maybe a -> Header
-contentRangeH lower upper total =
-    ("Content-Range", headerValue)
-    where
-      headerValue   = rangeString <> "/" <> totalString
-      rangeString
-        | totalNotZero && fromInRange = show lower <> "-" <> show upper
-        | otherwise = "*"
-      totalString   = maybe "*" show total
-      totalNotZero  = maybe True (0 /=) total
-      fromInRange   = lower <= upper
-
-extractQueryResult :: Maybe ResultsWithCount -> ResultsWithCount
-extractQueryResult = fromMaybe (Nothing, 0, [], "")
+contentProfileH :: Schema -> Header
+contentProfileH schema =
+   ("Content-Profile", toS schema)
@@ -31,7 +31,8 @@ import Control.Lens.Operators
 import Crypto.JWT

 import PostgREST.Types
-import Protolude
+import Protolude       hiding (toS)
+import Protolude.Conv  (toS)

 {-|
  Possible situations encountered with client JWTs
@@ -32,22 +32,23 @@ import qualified Data.CaseInsensitive         as CI
 import qualified Data.Configurator            as C
 import qualified Text.PrettyPrint.ANSI.Leijen as L

-import Control.Exception           (Handler (..))
 import Control.Lens                (preview)
 import Control.Monad               (fail)
 import Crypto.JWT                  (StringOrURI, stringOrUri)
 import Data.List                   (lookup)
+import Data.List.NonEmpty          (fromList)
 import Data.Scientific             (floatingOrInteger)
 import Data.Text                   (dropEnd, dropWhileEnd,
-                                    intercalate, lines, splitOn,
-                                    strip, take, unpack)
-import Data.Text.Encoding          (encodeUtf8)
+                                    intercalate, splitOn, strip, take,
+                                    unpack)
 import Data.Text.IO                (hPutStrLn)
 import Data.Version                (versionBranch)
 import Development.GitRev          (gitHash)
 import Network.Wai.Middleware.Cors (CorsResourcePolicy (..))
+import Numeric                     (readOct)
 import Paths_postgrest             (version)
 import System.IO.Error             (IOError)
+import System.Posix.Types          (FileMode)

 import Control.Applicative
 import Data.Monoid
@@ -58,21 +59,22 @@ import Text.PrettyPrint.ANSI.Leijen hiding ((<$>), (<>))

 import PostgREST.Error   (ApiRequestError (..))
 import PostgREST.Parsers (pRoleClaimKey)
-import PostgREST.Types   (JSPath, JSPathExp (..),
-                          QualifiedIdentifier (..))
+import PostgREST.Types   (JSPath, JSPathExp (..))
 import Protolude         hiding (concat, hPutStrLn, intercalate, null,
-                          take, (<>))
+                          take, toS, (<>))
+import Protolude.Conv    (toS)


 -- | Config file settings for the server
 data AppConfig = AppConfig {
    configDatabase          :: Text
  , configAnonRole          :: Text
-  , configProxyUri          :: Maybe Text
-  , configSchema            :: Text
+  , configOpenAPIProxyUri   :: Maybe Text
+  , configSchemas           :: NonEmpty Text
  , configHost              :: Text
  , configPort              :: Int
-  , configSocket            :: Maybe Text
+  , configSocket            :: Maybe FilePath
+  , configSocketMode        :: Either Text FileMode

  , configJwtSecret         :: Maybe B.ByteString
  , configJwtSecretIsBase64 :: Bool
@@ -87,7 +89,8 @@ data AppConfig = AppConfig {
  , configRoleClaimKey      :: Either ApiRequestError JSPath
  , configExtraSearchPath   :: [Text]

-  , configRootSpec          :: Maybe QualifiedIdentifier
+  , configRootSpec          :: Maybe Text
+  , configRawMediaTypes     :: [B.ByteString]
  }

 configPoolTimeout' :: (Fractional a) => AppConfig -> a
@@ -136,7 +139,7 @@ readOptions = do
  -- Now read the actual config file
  conf <- catches (C.load cfgPath)
    [ Handler (\(ex :: IOError)    -> exitErr $ "Cannot open config file:\n\t" <> show ex)
-    , Handler (\(C.ParseError err) -> exitErr $ "Error parsing config file:\n\t" <> err)
+    , Handler (\(C.ParseError err) -> exitErr $ "Error parsing config file:\n" <> err)
    ]

  case C.runParser parseConfig conf of
@@ -146,16 +149,16 @@ readOptions = do
      return appConf

  where
-    dbSchema = reqString "db-schema"
    parseConfig =
      AppConfig
        <$> reqString "db-uri"
        <*> reqString "db-anon-role"
-        <*> optString "server-proxy-uri"
-        <*> dbSchema
+        <*> optString "openapi-server-proxy-uri"
+        <*> (fromList . splitOnCommas <$> reqValue "db-schema")
        <*> (fromMaybe "!4" <$> optString "server-host")
        <*> (fromMaybe 3000 <$> optInt "server-port")
-        <*> optString "server-unix-socket"
+        <*> (fmap unpack <$> optString "server-unix-socket")
+        <*> parseSocketFileMode "server-unix-socket-mode"
        <*> (fmap encodeUtf8 <$> optString "jwt-secret")
        <*> (fromMaybe False <$> optBool "secret-is-base64")
        <*> parseJwtAudience "jwt-aud"
@@ -166,8 +169,22 @@ readOptions = do
        <*> pure False
        <*> (fmap (fmap coerceText) <$> C.subassocs "app.settings" C.value)
        <*> (maybe (Right [JSPKey "role"]) parseRoleClaimKey <$> optValue "role-claim-key")
-        <*> (maybe ["public"] splitExtraSearchPath <$> optValue "db-extra-search-path")
-        <*> ((\x y -> QualifiedIdentifier x <$> y) <$> dbSchema <*> optString "root-spec")
+        <*> (maybe ["public"] splitOnCommas <$> optValue "db-extra-search-path")
+        <*> optString "root-spec"
+        <*> (maybe [] (fmap encodeUtf8 . splitOnCommas) <$> optValue "raw-media-types")
+
+    parseSocketFileMode :: C.Key -> C.Parser C.Config (Either Text FileMode)
+    parseSocketFileMode k =
+      C.optional k C.string >>= \case
+        Nothing -> pure $ Right 432 -- return default 660 mode if no value was provided
+        Just fileModeText ->
+          case (readOct . unpack) fileModeText of
+            []              ->
+              pure $ Left "Invalid server-unix-socket-mode: not an octal"
+            (fileMode, _):_ ->
+              if fileMode < 384 || fileMode > 511
+                then pure $ Left "Invalid server-unix-socket-mode: needs to be between 600 and 777"
+                else pure $ Right fileMode

    parseJwtAudience :: C.Key -> C.Parser C.Config (Maybe StringOrURI)
    parseJwtAudience k =
@@ -181,6 +198,9 @@ readOptions = do
    reqString :: C.Key -> C.Parser C.Config Text
    reqString k = C.required k C.string

+    reqValue :: C.Key -> C.Parser C.Config C.Value
+    reqValue k = C.required k C.value
+
    optString :: C.Key -> C.Parser C.Config (Maybe Text)
    optString k = mfilter (/= "") <$> C.optional k C.string

@@ -211,9 +231,9 @@ readOptions = do
    parseRoleClaimKey (C.String s) = pRoleClaimKey s
    parseRoleClaimKey v            = pRoleClaimKey $ show v

-    splitExtraSearchPath :: C.Value -> [Text]
-    splitExtraSearchPath (C.String s) = strip <$> splitOn "," s
-    splitExtraSearchPath _            = []
+    splitOnCommas :: C.Value -> [Text]
+    splitOnCommas (C.String s) = strip <$> splitOn "," s
+    splitOnCommas _            = []

    opts = info (helper <*> pathParser) $
             fullDesc
@@ -248,13 +268,16 @@ readOptions = do
          |## unix socket location
          |## if specified it takes precedence over server-port
          |# server-unix-socket = "/tmp/pgrst.sock"
+          |## unix socket file mode
+          |## when none is provided, 660 is applied by default
+          |# server-unix-socket-mode = "660"
          |
          |## base url for swagger output
-          |# server-proxy-uri = ""
+          |# openapi-server-proxy-uri = ""
          |
          |## choose a secret, JSON Web Key (or set) to enable JWT auth
          |## (use "@filename" to load from separate file)
-          |# jwt-secret = "foo"
+          |# jwt-secret = "secret_with_at_least_32_characters"
          |# secret-is-base64 = false
          |# jwt-aud = "your_audience_claim"
          |
@@ -273,6 +296,9 @@ readOptions = do
          |## stored proc that overrides the root "/" spec
          |## it must be inside the db-schema
          |# root-spec = "stored_proc_name"
+          |
+          |## content types to produce raw output
+          |# raw-media-types="image/png, image/jpg"
          |]

 pathParser :: Parser FilePath
@@ -14,248 +14,218 @@ A query tree is built in case of resource embedding. By inferring the relationsh
 module PostgREST.DbRequestBuilder (
  readRequest
 , mutateRequest
-, fieldNames
+, returningCols
 ) where

-import qualified Data.ByteString.Char8 as BS
-import qualified Data.HashMap.Strict   as M
-import qualified Data.Set              as S
+import qualified Data.HashMap.Strict as M
+import qualified Data.Set            as S

 import Control.Arrow           ((***))
-import Control.Lens.Getter     (view)
-import Control.Lens.Tuple      (_1)
 import Data.Either.Combinators (mapLeft)
 import Data.Foldable           (foldr1)
 import Data.List               (delete)
-import Data.Maybe              (fromJust)
 import Data.Text               (isInfixOf)
-import Text.Regex.TDFA         ((=~))
-import Unsafe                  (unsafeHead)

 import Control.Applicative
 import Data.Tree
 import Network.Wai

-import PostgREST.ApiRequest (Action (..), ApiRequest (..),
-                             PreferRepresentation (..),
-                             PreferRepresentation (..), Target (..))
+import PostgREST.ApiRequest (Action (..), ApiRequest (..))
 import PostgREST.Error      (ApiRequestError (..), errorResponseFor)
 import PostgREST.Parsers
 import PostgREST.RangeQuery (NonnegRange, allRange, restrictRange)
 import PostgREST.Types
 import Protolude            hiding (from)

-readRequest :: Maybe Integer -> [Relation] -> Maybe ProcDescription -> ApiRequest -> Either Response ReadRequest
-readRequest maxRows allRels proc apiRequest  =
+readRequest :: Schema -> TableName -> Maybe Integer -> [Relation] -> ApiRequest -> Either Response ReadRequest
+readRequest schema rootTableName maxRows allRels apiRequest  =
  mapLeft errorResponseFor $
  treeRestrictRange maxRows =<<
-  augumentRequestWithJoin schema relations =<<
+  augmentRequestWithJoin schema rootRels =<<
  addFiltersOrdersRanges apiRequest <*>
-  (buildReadRequest <$> pRequestSelect (iSelect apiRequest))
+  (initReadRequest rootName <$> pRequestSelect sel)
  where
-    action = iAction apiRequest
-    (schema, rootTableName) = fromJust $ -- Make it safe
-      let target = iTarget apiRequest in
-      case target of
-        (TargetIdent (QualifiedIdentifier s t) ) -> Just (s, t)
-        (TargetProc  (QualifiedIdentifier s pName) _ ) -> Just (s, tName)
-          where
-            tName = case pdReturnType <$> proc of
-              Just (SetOf (Composite qi))  -> qiName qi
-              Just (Single (Composite qi)) -> qiName qi
-              _                            -> pName
+    sel = fromMaybe "*" $ iSelect apiRequest -- default to all columns requested (SELECT *) for a non existent ?select querystring param
+    (rootName, rootRels) = rootWithRels schema rootTableName allRels (iAction apiRequest)

-        _ -> Nothing
+-- Get the root table name with its relationships according to the Action type.
+-- This is done because of the shape of the final SQL Query. The mutation cases are wrapped in a WITH {sourceCTEName}(see Statements.hs).
+-- So we need a FROM {sourceCTEName} instead of FROM {tableName}.
+rootWithRels :: Schema -> TableName -> [Relation] -> Action -> (QualifiedIdentifier, [Relation])
+rootWithRels schema rootTableName allRels action = case action of
+  ActionRead _ -> (QualifiedIdentifier schema rootTableName, allRels) -- normal read case
+  _            -> (QualifiedIdentifier mempty sourceCTEName, mapMaybe toSourceRel allRels ++ allRels) -- mutation cases and calling proc
+  where
+    -- To enable embedding in the sourceCTEName cases we need to replace the foreign key tableName in the Relation
+    -- with {sourceCTEName}. This way findRel can find relationships with sourceCTEName.
+    toSourceRel :: Relation -> Maybe Relation
+    toSourceRel r@Relation{relTable=t}
+      | rootTableName == tableName t = Just $ r {relTable=t {tableName=sourceCTEName}}
+      | otherwise                    = Nothing

-    -- Build tree with a Depth attribute so when a self join occurs we can differentiate the parent and child tables by having
-    -- an alias like "table_depth", this is related to issue #987.
-    buildReadRequest :: [Tree SelectItem] -> ReadRequest
-    buildReadRequest fieldTree =
-      let rootDepth = 0
-          rootNodeName = if action == ActionRead then rootTableName else sourceCTEName in
-      foldr (treeEntry rootDepth) (Node (Select [] rootNodeName Nothing [] [] [] [] allRange, (rootNodeName, Nothing, Nothing, Nothing, rootDepth)) []) fieldTree
-      where
-        treeEntry :: Depth -> Tree SelectItem -> ReadRequest -> ReadRequest
-        treeEntry depth (Node fld@((fn, _),_,alias,relationDetail) fldForest) (Node (q, i) rForest) =
-          let nxtDepth = succ depth in
-          case fldForest of
-            [] -> Node (q {select=fld:select q}, i) rForest
-            _  -> Node (q, i) $
-                  foldr (treeEntry nxtDepth) (Node (Select [] fn Nothing [] [] [] [] allRange, (fn, Nothing, alias, relationDetail, nxtDepth)) []) fldForest:rForest
-
-    relations :: [Relation]
-    relations = case action of
-      ActionCreate   -> fakeSourceRelations ++ allRels
-      ActionUpdate   -> fakeSourceRelations ++ allRels
-      ActionDelete   -> fakeSourceRelations ++ allRels
-      ActionInvoke _ -> fakeSourceRelations ++ allRels
-      _              -> allRels
-      where fakeSourceRelations = mapMaybe (toSourceRelation rootTableName) allRels
-
-- in a relation where one of the tables matches "TableName"
-- replace the name to that table with pg_source
-- this "fake" relations is needed so that in a mutate query
-- we can look at the "returning *" part which is wrapped with a "with"
-- as just another table that has relations with other tables
-toSourceRelation :: TableName -> Relation -> Maybe Relation
-toSourceRelation mt r@(Relation t _ ft _ _ rt _ _)
-  | mt == tableName t = Just $ r {relTable=t {tableName=sourceCTEName}}
-  | mt == tableName ft = Just $ r {relFTable=t {tableName=sourceCTEName}}
-  | Just mt == (tableName <$> rt) = Just $ r {relLinkTable=(\tbl -> tbl {tableName=sourceCTEName}) <$> rt}
-  | otherwise = Nothing
+-- Build the initial tree with a Depth attribute so when a self join occurs we can differentiate the parent and child tables by having
+-- an alias like "table_depth", this is related to http://github.com/PostgREST/postgrest/issues/987.
+initReadRequest :: QualifiedIdentifier -> [Tree SelectItem] -> ReadRequest
+initReadRequest rootQi =
+  foldr (treeEntry rootDepth) initial
+  where
+    rootDepth = 0
+    rootSchema = qiSchema rootQi
+    rootName = qiName rootQi
+    initial = Node (Select [] rootQi Nothing [] [] [] [] allRange, (rootName, Nothing, Nothing, Nothing, rootDepth)) []
+    treeEntry :: Depth -> Tree SelectItem -> ReadRequest -> ReadRequest
+    treeEntry depth (Node fld@((fn, _),_,alias, embedHint) fldForest) (Node (q, i) rForest) =
+      let nxtDepth = succ depth in
+      case fldForest of
+        [] -> Node (q {select=fld:select q}, i) rForest
+        _  -> Node (q, i) $
+              foldr (treeEntry nxtDepth)
+              (Node (Select [] (QualifiedIdentifier rootSchema fn) Nothing [] [] [] [] allRange,
+                (fn, Nothing, alias, embedHint, nxtDepth)) [])
+              fldForest:rForest

 treeRestrictRange :: Maybe Integer -> ReadRequest -> Either ApiRequestError ReadRequest
-treeRestrictRange maxRows_ request = pure $ nodeRestrictRange maxRows_ `fmap` request
+treeRestrictRange maxRows request = pure $ nodeRestrictRange maxRows <$> request
  where
    nodeRestrictRange :: Maybe Integer -> ReadNode -> ReadNode
    nodeRestrictRange m (q@Select {range_=r}, i) = (q{range_=restrictRange m r }, i)

-augumentRequestWithJoin :: Schema ->  [Relation] ->  ReadRequest -> Either ApiRequestError ReadRequest
-augumentRequestWithJoin schema allRels request =
-  addRelations schema allRels Nothing request
-  >>= addJoinConditions schema Nothing
+augmentRequestWithJoin :: Schema -> [Relation] -> ReadRequest -> Either ApiRequestError ReadRequest
+augmentRequestWithJoin schema allRels request =
+  addRels schema allRels Nothing request
+  >>= addJoinConditions Nothing

-addRelations :: Schema -> [Relation] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
-addRelations schema allRelations parentNode (Node (query@Select{from=tbl}, (nodeName, _, alias, relationDetail, depth)) forest) =
+addRels :: Schema -> [Relation] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
+addRels schema allRels parentNode (Node (query@Select{from=tbl}, (nodeName, _, alias, hint, depth)) forest) =
  case parentNode of
-    Just (Node (Select{from=parentNodeTable}, _) _) ->
-      let newFrom r = if tbl == nodeName then tableName (relTable r) else tbl
+    Just (Node (Select{from=parentNodeQi}, _) _) ->
+      let newFrom r = if qiName tbl == nodeName then tableQi (relFTable r) else tbl
          newReadNode = (\r -> (query{from=newFrom r}, (nodeName, Just r, alias, Nothing, depth))) <$> rel
-          rel :: Either ApiRequestError Relation
-          rel = note (NoRelationBetween parentNodeTable nodeName) $
-                findRelation schema allRelations nodeName parentNodeTable relationDetail in
+          rel = findRel schema allRels (qiName parentNodeQi) nodeName hint
+      in
      Node <$> newReadNode <*> (updateForest . hush $ Node <$> newReadNode <*> pure forest)
    _ ->
-      let rn = (query, (nodeName, Just r, alias, Nothing, depth))
-          r = Relation t [] t [] Root Nothing Nothing Nothing
-          t = Table schema nodeName Nothing True in -- !!! TODO find another way to get the table from the query
+      let rn = (query, (nodeName, Nothing, alias, Nothing, depth)) in
      Node rn <$> updateForest (Just $ Node rn forest)
  where
    updateForest :: Maybe ReadRequest -> Either ApiRequestError [ReadRequest]
-    updateForest rq = mapM (addRelations schema allRelations rq) forest
+    updateForest rq = mapM (addRels schema allRels rq) forest

-findRelation :: Schema -> [Relation] -> NodeName -> TableName -> Maybe RelationDetail -> Maybe Relation
-findRelation schema allRelations nodeTableName parentNodeTableName relationDetail =
-  find (\Relation{relTable, relColumns, relFTable, relFColumns, relType, relLinkTable} ->
-    -- Both relation ends need to be on the exposed schema
-    schema == tableSchema relTable && schema == tableSchema relFTable &&
-    case relationDetail of
-      Nothing ->
-
-        -- (request)        => projects { ..., clients{...} }
-        -- will match
-        -- (relation type)  => parent
-        -- (entity)         => clients  {id}
-        -- (foriegn entity) => projects {client_id}
+-- Finds a relationship between an origin and a target in the request: /origin?select=target(*)
+-- If more than one relationship is found then the request is ambiguous and we return an error.
+-- In that case the request can be disambiguated by adding precision to the target or by using a hint: /origin?select=target!hint(*)
+-- The elements will be matched according to these rules:
+-- origin = table / view
+-- target = table / view / constraint / column-from-origin
+-- hint   = table / view / constraint / column-from-origin / column-from-target
+-- (hint can take table / view values to aid in finding the junction in an m2m relationship)
+findRel :: Schema -> [Relation] -> NodeName -> NodeName -> Maybe EmbedHint -> Either ApiRequestError Relation
+findRel schema allRels origin target hint =
+  case rel of
+    []  -> Left $ NoRelBetween origin target
+    [r] -> Right r
+    rs  ->
+      -- Return error if more than one relationship is found, unless we're in a self reference case.
+      --
+      -- Here we handle a self reference relationship to not cause a breaking change:
+      -- In a self reference we get two relationships with the same foreign key and relTable/relFtable but with different cardinalities(m2o/o2m)
+      -- We output the O2M rel, the M2O rel can be obtained by using the origin column as an embed hint.
+      let [rel0, rel1] = take 2 rs in
+      if length rs == 2 && relConstraint rel0 == relConstraint rel1 && relTable rel0 == relTable rel1 && relFTable rel0 == relFTable rel1
+        then note (NoRelBetween origin target) (find (\r -> relType r == O2M) rs)
+        else Left $ AmbiguousRelBetween origin target rs
+  where
+    matchFKSingleCol hint_ cols = length cols == 1 && hint_ == (colName <$> head cols)
+    rel = filter (
+      \Relation{relTable, relColumns, relConstraint, relFTable, relFColumns, relType, relJunction} ->
+        -- Both relationship ends need to be on the exposed schema
+        schema == tableSchema relTable && schema == tableSchema relFTable &&
        (
-          nodeTableName == tableName relTable && -- match relation table name
-          parentNodeTableName == tableName relFTable -- match relation foreign table name
-        ) ||
+          -- /projects?select=clients(*)
+          origin == tableName relTable  &&  -- projects
+          target == tableName relFTable ||  -- clients

-        -- (request)        => projects { ..., client_id{...} }
-        -- will match
-        -- (relation type)  => parent
-        -- (entity)         => clients  {id}
-        -- (foriegn entity) => projects {client_id}
-        (
-          parentNodeTableName == tableName relFTable &&
-          length relFColumns == 1 &&
-          -- match common foreign key names(table_name_id, table_name_fk) to table_name
-          (toS ("^" <> colName (unsafeHead relFColumns) <> "_?(?:|[iI][dD]|[fF][kK])$") :: BS.ByteString) =~ (toS nodeTableName :: BS.ByteString)
+          -- /projects?select=projects_client_id_fkey(*)
+          (
+            origin == tableName relTable && -- projects
+            Just target == relConstraint    -- projects_client_id_fkey
+          ) ||
+          -- /projects?select=client_id(*)
+          (
+            origin == tableName relTable &&           -- projects
+            matchFKSingleCol (Just target) relColumns -- client_id
+          )
+        ) && (
+          isNothing hint || -- hint is optional
+
+          -- /projects?select=clients!projects_client_id_fkey(*)
+          hint == relConstraint             || -- projects_client_id_fkey
+
+          -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
+          matchFKSingleCol hint relColumns  || -- client_id
+          matchFKSingleCol hint relFColumns || -- id
+
+          -- /users?select=tasks!users_tasks(*)
+          (
+            relType == M2M &&                              -- many-to-many between users and tasks
+            hint == (tableName . junTable <$> relJunction) -- users_tasks
+          )
        )
-
-        -- (request)        => project_id { ..., client_id{...} }
-        -- will match
-        -- (relation type)  => parent
-        -- (entity)         => clients  {id}
-        -- (foriegn entity) => projects {client_id}
-        -- this case works becasue before reaching this place
-        -- addRelation will turn project_id to project so the above condition will match
-
-      Just rd ->
-
-        -- (request)        => clients { ..., projects.client_id{...} }
-        -- will match
-        -- (relation type)  => child
-        -- (entity)         => clients  {id}
-        -- (foriegn entity) => projects {client_id}
-        (
-          relType == Child &&
-          nodeTableName == tableName relTable && -- match relation table name
-          parentNodeTableName == tableName relFTable && -- match relation foreign table name
-          length relColumns == 1 &&
-          rd == colName (unsafeHead relColumns)
-        ) ||
-
-        -- (request)        => message { ..., person_detail.sender{...} }
-        -- will match
-        -- (relation type)  => parent
-        -- (entity)         => message  {sender}
-        -- (foriegn entity) => person_detail {id}
-        (
-          relType == Parent &&
-          nodeTableName == tableName relTable && -- match relation table name
-          parentNodeTableName == tableName relFTable && -- match relation foreign table name
-          length relFColumns == 1 &&
-          rd == colName (unsafeHead relFColumns)
-        ) ||
-
-        -- (request)        => tasks { ..., users.tasks_users{...} }
-        -- will match
-        -- (relation type)  => many
-        -- (entity)         => users
-        -- (foriegn entity) => tasks
-        (
-          relType == Many &&
-          nodeTableName == tableName relTable && -- match relation table name
-          parentNodeTableName == tableName relFTable && -- match relation foreign table name
-          rd == tableName (fromJust relLinkTable)
-        )
-  ) allRelations
+      ) allRels

 -- previousAlias is only used for the case of self joins
-addJoinConditions :: Schema -> Maybe Alias -> ReadRequest -> Either ApiRequestError ReadRequest
-addJoinConditions schema previousAlias (Node node@(query@Select{from=tbl}, nodeProps@(_, relation, _, _, depth)) forest) =
-  case relation of
-    Just Relation{relType=Root} -> Node node <$> updatedForest -- this is the root node
-    Just rel@Relation{relType=Parent} -> Node (augmentQuery rel, nodeProps) <$> updatedForest
-    Just rel@Relation{relType=Child} -> Node (augmentQuery rel, nodeProps) <$> updatedForest
-    Just rel@Relation{relType=Many, relLinkTable=(Just linkTable)} ->
-      let rq = augmentQuery rel in
-      Node (rq{implicitJoins=tableName linkTable:implicitJoins rq}, nodeProps) <$> updatedForest
-    _ -> Left UnknownRelation
+addJoinConditions :: Maybe Alias -> ReadRequest -> Either ApiRequestError ReadRequest
+addJoinConditions previousAlias (Node node@(query@Select{from=tbl}, nodeProps@(_, rel, _, _, depth)) forest) =
+  case rel of
+    Just r@Relation{relType=O2M} -> Node (augmentQuery r, nodeProps) <$> updatedForest
+    Just r@Relation{relType=M2O} -> Node (augmentQuery r, nodeProps) <$> updatedForest
+    Just r@Relation{relType=M2M, relJunction=junction} ->
+      case junction of
+        Just Junction{junTable} ->
+          let rq = augmentQuery r in
+          Node (rq{implicitJoins=tableQi junTable:implicitJoins rq}, nodeProps) <$> updatedForest
+        Nothing ->
+          Left UnknownRelation
+    Nothing -> Node node <$> updatedForest
  where
-    newAlias = case isSelfJoin <$> relation of
+    newAlias = case isSelfReference <$> rel of
      Just True
-        | depth /= 0 -> Just (tbl <> "_" <> show depth) -- root node doesn't get aliased
+        | depth /= 0 -> Just (qiName tbl <> "_" <> show depth) -- root node doesn't get aliased
        | otherwise  -> Nothing
      _              -> Nothing
-    augmentQuery rel =
+    augmentQuery r =
      foldr
        (\jc rq@Select{joinConditions=jcs} -> rq{joinConditions=jc:jcs})
        query{fromAlias=newAlias}
-        (getJoinConditions previousAlias newAlias rel)
-    updatedForest = mapM (addJoinConditions schema newAlias) forest
+        (getJoinConditions previousAlias newAlias r)
+    updatedForest = mapM (addJoinConditions newAlias) forest

 -- previousAlias and newAlias are used in the case of self joins
 getJoinConditions :: Maybe Alias -> Maybe Alias -> Relation -> [JoinCondition]
-getJoinConditions previousAlias newAlias (Relation Table{tableSchema=tSchema, tableName=tN} cols Table{tableName=ftN} fCols typ lt lc1 lc2) =
+getJoinConditions previousAlias newAlias (Relation Table{tableSchema=tSchema, tableName=tN} cols _ Table{tableName=ftN} fCols typ jun) =
  case typ of
-    Child  ->
+    O2M ->
        zipWith (toJoinCondition tN ftN) cols fCols
-    Parent ->
+    M2O ->
        zipWith (toJoinCondition tN ftN) cols fCols
-    Many   ->
-        let ltN = maybe "" tableName lt in
-        zipWith (toJoinCondition tN ltN) cols (fromMaybe [] lc1) ++ zipWith (toJoinCondition ftN ltN) fCols (fromMaybe [] lc2)
-    Root   -> witness
+    M2M -> case jun of
+        Just (Junction jt _ jc1 _ jc2) ->
+          let jtn = tableName jt in
+          zipWith (toJoinCondition tN jtn) cols jc1 ++ zipWith (toJoinCondition ftN jtn) fCols jc2
+        Nothing -> []
  where
    toJoinCondition :: Text -> Text -> Column -> Column -> JoinCondition
    toJoinCondition tb ftb c fc =
-      let qi1 = QualifiedIdentifier tSchema tb
-          qi2 = QualifiedIdentifier tSchema ftb in
-        JoinCondition (maybe qi1 (QualifiedIdentifier mempty) newAlias, colName c)
-                      (maybe qi2 (QualifiedIdentifier mempty) previousAlias, colName fc)
+      let qi1 = removeSourceCTESchema tSchema tb
+          qi2 = removeSourceCTESchema tSchema ftb in
+        JoinCondition (maybe qi1 (QualifiedIdentifier mempty) previousAlias, colName c)
+                      (maybe qi2 (QualifiedIdentifier mempty) newAlias, colName fc)
+
+    -- On mutation and calling proc cases we wrap the target table in a WITH {sourceCTEName}
+    -- if this happens remove the schema `FROM "schema"."{sourceCTEName}"` and use only the
+    -- `FROM "{sourceCTEName}"`. If the schema remains the FROM would be invalid.
+    removeSourceCTESchema :: Schema -> TableName -> QualifiedIdentifier
+    removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == sourceCTEName then mempty else schema) tbl

 addFiltersOrdersRanges :: ApiRequest -> Either ApiRequestError (ReadRequest -> ReadRequest)
 addFiltersOrdersRanges apiRequest = foldr1 (liftA2 (.)) [
@@ -266,7 +236,7 @@ addFiltersOrdersRanges apiRequest = foldr1 (liftA2 (.)) [
  ]
  {-
  The esence of what is going on above is that we are composing tree functions
-  of type (ReadRequest->ReadRequest) that are in (Either ParseError a) context
+  of type (ReadRequest->ReadRequest) that are in (Either ApiRequestError a) context
  -}
  where
    filters :: Either ApiRequestError [(EmbedPath, Filter)]
@@ -278,7 +248,7 @@ addFiltersOrdersRanges apiRequest = foldr1 (liftA2 (.)) [
    (flts, logFrst) =
      case action of
        ActionInvoke _ -> (iFilters apiRequest, iLogic apiRequest)
-        ActionRead     -> (iFilters apiRequest, iLogic apiRequest)
+        ActionRead _   -> (iFilters apiRequest, iLogic apiRequest)
        _              -> join (***) (filter (( "." `isInfixOf` ) . fst)) (iFilters apiRequest, iLogic apiRequest)
    orders :: Either ApiRequestError [(EmbedPath, [OrderTerm])]
    orders = mapM pRequestOrder $ iOrder apiRequest
@@ -318,11 +288,15 @@ addProperty f (targetNodeName:remainingPath, a) (Node rn forest) =
  where
    pathNode = find (\(Node (_,(nodeName,_,alias,_,_)) _) -> nodeName == targetNodeName || alias == Just targetNodeName) forest

-mutateRequest :: ApiRequest -> TableName -> S.Set FieldName -> [FieldName] -> [FieldName] -> Either Response MutateRequest
-mutateRequest apiRequest tName cols pkCols fldNames = mapLeft errorResponseFor $
+mutateRequest :: Schema -> TableName -> ApiRequest -> S.Set FieldName -> [FieldName] -> ReadRequest -> Either Response MutateRequest
+mutateRequest schema tName apiRequest cols pkCols readReq = mapLeft errorResponseFor $
  case action of
-    ActionCreate -> Right $ Insert tName cols ((,) <$> iPreferResolution apiRequest <*> Just pkCols) [] returnings
-    ActionUpdate -> Update tName cols <$> combinedLogic <*> pure returnings
+    ActionCreate -> do
+        confCols <- case iOnConflict apiRequest of
+            Nothing    -> pure pkCols
+            Just param -> pRequestOnConflict param
+        pure $ Insert qi cols ((,) <$> iPreferResolution apiRequest <*> Just confCols) [] returnings
+    ActionUpdate -> Update qi cols <$> combinedLogic <*> pure returnings
    ActionSingleUpsert ->
      (\flts ->
        if null (iLogic apiRequest) &&
@@ -331,14 +305,18 @@ mutateRequest apiRequest tName cols pkCols fldNames = mapLeft errorResponseFor $
           all (\case
              Filter _ (OpExpr False (Op "eq" _)) -> True
              _ -> False) flts
-          then Insert tName cols (Just (MergeDuplicates, pkCols)) <$> combinedLogic <*> pure returnings
+          then Insert qi cols (Just (MergeDuplicates, pkCols)) <$> combinedLogic <*> pure returnings
        else
          Left InvalidFilters) =<< filters
-    ActionDelete -> Delete tName <$> combinedLogic <*> pure returnings
+    ActionDelete -> Delete qi <$> combinedLogic <*> pure returnings
    _            -> Left UnsupportedVerb
  where
+    qi = QualifiedIdentifier schema tName
    action = iAction apiRequest
-    returnings = if iPreferRepresentation apiRequest == None then [] else fldNames
+    returnings =
+      if iPreferRepresentation apiRequest == None
+        then []
+        else returningCols readReq
    filters = map snd <$> mapM pRequestFilter mutateFilters
    logic = map snd <$> mapM pRequestLogicTree logicFilters
    combinedLogic = foldr addFilterToLogicForest <$> logic <*> filters
@@ -346,13 +324,26 @@ mutateRequest apiRequest tName cols pkCols fldNames = mapLeft errorResponseFor $
    (mutateFilters, logicFilters) = join (***) onlyRoot (iFilters apiRequest, iLogic apiRequest)
    onlyRoot = filter (not . ( "." `isInfixOf` ) . fst)

-fieldNames :: ReadRequest -> [FieldName]
-fieldNames (Node (sel, _) forest) =
-  map (fst . view _1) (select sel) ++ map colName fks
+returningCols :: ReadRequest -> [FieldName]
+returningCols rr@(Node _ forest) = returnings
  where
-    fks = concatMap (fromMaybe [] . f) forest
-    f (Node (_, (_, Just Relation{relFColumns=cols, relType=Parent}, _, _, _)) _) = Just cols
-    f _ = Nothing
+    fldNames = fstFieldNames rr
+    -- Without fkCols, when a mutateRequest to /projects?select=name,clients(name) occurs, the RETURNING SQL part would be
+    -- `RETURNING name`(see QueryBuilder).
+    -- This would make the embedding fail because the following JOIN would need the "client_id" column from projects.
+    -- So this adds the foreign key columns to ensure the embedding succeeds, result would be `RETURNING name, client_id`.
+    -- This also works for the other relType's.
+    fkCols = concat $ mapMaybe (\case
+        Node (_, (_, Just Relation{relColumns=cols, relType=relTyp}, _, _, _)) _ -> case relTyp of
+          O2M -> Just cols
+          M2O -> Just cols
+          M2M -> Just cols
+        _ -> Nothing
+      ) forest
+    -- However if the "client_id" is present, e.g. mutateRequest to /projects?select=client_id,name,clients(name)
+    -- we would get `RETURNING client_id, name, client_id` and then we would produce the "column reference \"client_id\" is ambiguous"
+    -- error from PostgreSQL. So we deduplicate with Set:
+    returnings = S.toList . S.fromList $ fldNames ++ (colName <$> fkCols)

 -- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
 -- they are later concatenated with AND in the QueryBuilder
@@ -35,39 +35,27 @@ import Data.Set                      as S (fromList)
 import Data.Text                     (breakOn, dropAround, split,
                                      splitOn, strip)
 import GHC.Exts                      (groupWith)
+import Protolude                     hiding (toS)
+import Protolude.Conv                (toS)
+import Protolude.Unsafe              (unsafeHead)
 import Text.InterpolatedString.Perl6 (q, qc)
-import Unsafe                        (unsafeHead)
-
-import Control.Applicative

+import PostgREST.Private.Common
 import PostgREST.Types
-import Protolude

-column :: HD.Value a -> HD.Row a
-column = HD.column . HD.nonNullable
+getDbStructure :: [Schema] -> PgVersion -> HT.Transaction DbStructure
+getDbStructure schemas pgVer = do
+  HT.sql "set local schema ''" -- This voids the search path. The following queries need this for getting the fully qualified name(schema.name) of every db object
+  tabs    <- HT.statement () allTables
+  cols    <- HT.statement schemas $ allColumns tabs
+  srcCols <- HT.statement schemas $ allSourceColumns cols pgVer
+  m2oRels <- HT.statement () $ allM2ORels tabs cols
+  keys    <- HT.statement () $ allPrimaryKeys tabs
+  procs   <- HT.statement schemas allProcs

-nullableColumn :: HD.Value a -> HD.Row (Maybe a)
-nullableColumn = HD.column . HD.nullable
-
-element :: HD.Value a -> HD.Array a
-element = HD.element . HD.nonNullable
-
-param :: HE.Value a -> HE.Params a
-param = HE.param . HE.nonNullable
-
-getDbStructure :: Schema -> PgVersion -> HT.Transaction DbStructure
-getDbStructure schema pgVer = do
-  HT.sql "set local schema ''" -- for getting the fully qualified name(schema.name) of every db object
-  tabs      <- HT.statement () allTables
-  cols      <- HT.statement schema $ allColumns tabs
-  syns      <- HT.statement schema $ allSynonyms cols pgVer
-  childRels <- HT.statement () $ allChildRelations tabs cols
-  keys      <- HT.statement () $ allPrimaryKeys tabs
-  procs     <- HT.statement schema allProcs
-
-  let rels = addManyToManyRelations . addParentRelations $ addViewChildRelations syns childRels
+  let rels = addM2MRels . addO2MRels $ addViewM2ORels srcCols m2oRels
      cols' = addForeignKeys rels cols
-      keys' = addViewPrimaryKeys syns keys
+      keys' = addViewPrimaryKeys srcCols keys

  return DbStructure {
      dbTables = tabs
@@ -102,13 +90,14 @@ decodeColumns tables =
      <*> nullableColumn HD.text
      <*> nullableColumn HD.text

-decodeRelations :: [Table] -> [Column] -> HD.Result [Relation]
-decodeRelations tables cols =
-  mapMaybe (relationFromRow tables cols) <$> HD.rowList relRow
+decodeRels :: [Table] -> [Column] -> HD.Result [Relation]
+decodeRels tables cols =
+  mapMaybe (relFromRow tables cols) <$> HD.rowList relRow
 where
-  relRow = (,,,,,)
+  relRow = (,,,,,,)
    <$> column HD.text
    <*> column HD.text
+    <*> column HD.text
    <*> column (HD.array (HD.dimension replicateM (element HD.text)))
    <*> column HD.text
    <*> column HD.text
@@ -120,22 +109,30 @@ decodePks tables =
 where
  pkRow = (,,) <$> column HD.text <*> column HD.text <*> column HD.text

-decodeSynonyms :: [Column] -> HD.Result [Synonym]
-decodeSynonyms cols =
-  mapMaybe (synonymFromRow cols) <$> HD.rowList synRow
+decodeSourceColumns :: [Column] -> HD.Result [SourceColumn]
+decodeSourceColumns cols =
+  mapMaybe (sourceColumnFromRow cols) <$> HD.rowList srcColRow
 where
-  synRow = (,,,,,)
+  srcColRow = (,,,,,)
    <$> column HD.text <*> column HD.text
    <*> column HD.text <*> column HD.text
    <*> column HD.text <*> column HD.text

-decodeProcs :: HD.Result (M.HashMap Text [ProcDescription])
+sourceColumnFromRow :: [Column] -> (Text,Text,Text,Text,Text,Text) -> Maybe SourceColumn
+sourceColumnFromRow allCols (s1,t1,c1,s2,t2,c2) = (,) <$> col1 <*> col2
+  where
+    col1 = findCol s1 t1 c1
+    col2 = findCol s2 t2 c2
+    findCol s t c = find (\col -> (tableSchema . colTable) col == s && (tableName . colTable) col == t && colName col == c) allCols
+
+decodeProcs :: HD.Result ProcsMap
 decodeProcs =
  -- Duplicate rows for a function means they're overloaded, order these by least args according to ProcDescription Ord instance
-  map sort . M.fromListWith (++) . map ((\(x,y) -> (x, [y])) . addName) <$> HD.rowList tblRow
+  map sort . M.fromListWith (++) . map ((\(x,y) -> (x, [y])) . addKey) <$> HD.rowList procRow
  where
-    tblRow = ProcDescription
+    procRow = ProcDescription
              <$> column HD.text
+              <*> column HD.text
              <*> nullableColumn HD.text
              <*> (parseArgs <$> column HD.text)
              <*> (parseRetType
@@ -145,8 +142,8 @@ decodeProcs =
                  <*> column HD.char)
              <*> (parseVolatility <$> column HD.char)

-    addName :: ProcDescription -> (Text, ProcDescription)
-    addName pd = (pdName pd, pd)
+    addKey :: ProcDescription -> (QualifiedIdentifier, ProcDescription)
+    addKey pd = (QualifiedIdentifier (pdSchema pd) (pdName pd), pd)

    parseArgs :: Text -> [PgArg]
    parseArgs = mapMaybe parseArg . filter (not . isPrefixOf "OUT" . toS) . map strip . split (==',')
@@ -179,31 +176,34 @@ decodeProcs =
                      | v == 's' = Stable
                      | otherwise = Volatile -- only 'v' can happen here

-allProcs :: H.Statement Schema (M.HashMap Text [ProcDescription])
-allProcs = H.Statement (toS procsSqlQuery) (param HE.text) decodeProcs True
+allProcs :: H.Statement [Schema] ProcsMap
+allProcs = H.Statement (toS sql) (arrayParam HE.text) decodeProcs True
+  where
+    sql = procsSqlQuery <> " WHERE pn.nspname = ANY($1)"

-accessibleProcs :: H.Statement Schema (M.HashMap Text [ProcDescription])
+accessibleProcs :: H.Statement Schema ProcsMap
 accessibleProcs = H.Statement (toS sql) (param HE.text) decodeProcs True
  where
-    sql = procsSqlQuery <> " AND has_function_privilege(p.oid, 'execute')"
+    sql = procsSqlQuery <> " WHERE pn.nspname = $1 AND has_function_privilege(p.oid, 'execute')"

 procsSqlQuery :: SqlQuery
 procsSqlQuery = [q|
-  SELECT p.proname as "proc_name",
-         d.description as "proc_description",
-         pg_get_function_arguments(p.oid) as "args",
-         tn.nspname as "rettype_schema",
-         coalesce(comp.relname, t.typname) as "rettype_name",
-         p.proretset as "rettype_is_setof",
-         t.typtype as "rettype_typ",
-         p.provolatile
+  SELECT
+    pn.nspname as proc_schema,
+    p.proname as proc_name,
+    d.description as proc_description,
+    pg_get_function_arguments(p.oid) as args,
+    tn.nspname as rettype_schema,
+    coalesce(comp.relname, t.typname) as rettype_name,
+    p.proretset as rettype_is_setof,
+    t.typtype as rettype_typ,
+    p.provolatile
  FROM pg_proc p
    JOIN pg_namespace pn ON pn.oid = p.pronamespace
    JOIN pg_type t ON t.oid = p.prorettype
    JOIN pg_namespace tn ON tn.oid = t.typnamespace
    LEFT JOIN pg_class comp ON comp.oid = t.typrelid
    LEFT JOIN pg_catalog.pg_description as d on d.objoid = p.oid
-  WHERE  pn.nspname = $1
 |]

 schemaDescription :: H.Statement Schema (Maybe Text)
@@ -228,11 +228,22 @@ accessibleTables =
      n.nspname as table_schema,
      relname as table_name,
      d.description as table_description,
-      c.relkind = 'r' or (c.relkind IN ('v', 'f')) and (pg_relation_is_updatable(c.oid::regclass, false) & 8) = 8
-      or (exists (
-         select 1
-         from pg_trigger
-         where pg_trigger.tgrelid = c.oid and (pg_trigger.tgtype::integer & 69) = 69)
+      (
+        c.relkind in ('r', 'v', 'f')
+        and (pg_relation_is_updatable(c.oid::regclass, false) & 8) = 8
+        -- The function `pg_relation_is_updateable` returns a bitmask where 8
+        -- corresponds to `1 << CMD_INSERT` in the PostgreSQL source code, i.e.
+        -- it's possible to insert into the relation.
+        or (exists (
+          select 1
+          from pg_trigger
+          where
+            pg_trigger.tgrelid = c.oid
+            and (pg_trigger.tgtype::integer & 69) = 69)
+            -- The trigger type `tgtype` is a bitmask where 69 corresponds to
+            -- TRIGGER_TYPE_ROW + TRIGGER_TYPE_INSTEAD + TRIGGER_TYPE_INSERT
+            -- in the PostgreSQL source code.
+        )
      ) as insertable
    from
      pg_class c
@@ -242,9 +253,9 @@ accessibleTables =
      c.relkind in ('v', 'r', 'm', 'f')
      and n.nspname = $1
      and (
-        pg_has_role(c.relowner, 'USAGE'::text)
-        or has_table_privilege(c.oid, 'SELECT, INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, TRIGGER'::text)
-        or has_any_column_privilege(c.oid, 'SELECT, INSERT, UPDATE, REFERENCES'::text)
+        pg_has_role(c.relowner, 'USAGE')
+        or has_table_privilege(c.oid, 'SELECT, INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, TRIGGER')
+        or has_any_column_privilege(c.oid, 'SELECT, INSERT, UPDATE, REFERENCES')
      )
    order by relname |]

@@ -254,20 +265,20 @@ addForeignKeys rels = map addFk
    addFk col = col { colFK = fk col }
    fk col = find (lookupFn col) rels >>= relToFk col
    lookupFn :: Column -> Relation -> Bool
-    lookupFn c Relation{relColumns=cs, relType=rty} = c `elem` cs && rty==Child
+    lookupFn c Relation{relColumns=cs, relType=rty} = c `elem` cs && rty==M2O
    relToFk col Relation{relColumns=cols, relFColumns=colsF} = do
      pos <- L.elemIndex col cols
      colF <- atMay colsF pos
      return $ ForeignKey colF

 {-
-Adds Views Child Relations based on Synonyms found, the logic is as follows:
+Adds Views M2O Relations based on SourceColumns found, the logic is as follows:

-Having a Relation{relTable=t1, relColumns=[c1], relFTable=t2, relFColumns=[c2], relType=Child} represented by:
+Having a Relation{relTable=t1, relColumns=[c1], relFTable=t2, relFColumns=[c2], relType=M2O} represented by:

 t1.c1------t2.c2

-When only having a t1_view.c1 synonym, we need to add a View to Table Child Relation
+When only having a t1_view.c1 source column, we need to add a View-Table M2O Relation

         t1.c1----t2.c2         t1.c1----------t2.c2
                         ->            ________/
@@ -275,70 +286,72 @@ When only having a t1_view.c1 synonym, we need to add a View to Table Child Rela
      t1_view.c1             t1_view.c1


-When only having a t2_view.c2 synonym, we need to add a Table to View Child Relation
+When only having a t2_view.c2 source column, we need to add a Table-View M2O Relation

         t1.c1----t2.c2               t1.c1----------t2.c2
                               ->          \________
                                                    \
                    t2_view.c2                      t2_view.c1

-When having t1_view.c1 and a t2_view.c2 synonyms, we need to add a View to View Child Relation in addition to the prior
+When having t1_view.c1 and a t2_view.c2 source columns, we need to add a View-View M2O Relation in addition to the prior

         t1.c1----t2.c2               t1.c1----------t2.c2
                               ->          \________/
                                           /        \
    t1_view.c1     t2_view.c2     t1_view.c1-------t2_view.c1

-The logic for composite pks is similar just need to make sure all the Relation columns have synonyms.
+The logic for composite pks is similar just need to make sure all the Relation columns have source columns.
 -}
-addViewChildRelations :: [Synonym] -> [Relation] -> [Relation]
-addViewChildRelations allSyns = concatMap (\rel ->
+addViewM2ORels :: [SourceColumn] -> [Relation] -> [Relation]
+addViewM2ORels allSrcCols = concatMap (\rel ->
  rel : case rel of
-    Relation{relType=Child, relTable, relColumns, relFTable, relFColumns} ->
+    Relation{relType=M2O, relTable, relColumns, relConstraint, relFTable, relFColumns} ->

-      let colSynsGroupedByView :: [Column] -> [[Synonym]]
-          colSynsGroupedByView relCols = L.groupBy (\(_, viewCol1) (_, viewCol2) -> colTable viewCol1 == colTable viewCol2) $
-                                         filter (\(c, _) -> c `elem` relCols) allSyns
-          colsSyns = colSynsGroupedByView relColumns
-          fColsSyns = colSynsGroupedByView relFColumns
-          getView :: [Synonym] -> Table
+      let srcColsGroupedByView :: [Column] -> [[SourceColumn]]
+          srcColsGroupedByView relCols = L.groupBy (\(_, viewCol1) (_, viewCol2) -> colTable viewCol1 == colTable viewCol2) $
+                                         filter (\(c, _) -> c `elem` relCols) allSrcCols
+          relSrcCols = srcColsGroupedByView relColumns
+          relFSrcCols = srcColsGroupedByView relFColumns
+          getView :: [SourceColumn] -> Table
          getView = colTable . snd . unsafeHead
-          syns `allSynsOf` cols = S.fromList (fst <$> syns) == S.fromList cols
+          srcCols `allSrcColsOf` cols = S.fromList (fst <$> srcCols) == S.fromList cols
          -- Relation is dependent on the order of relColumns and relFColumns to get the join conditions right in the generated query.
-          -- So we need to change the order of the synonyms to match the relColumns
-          -- This could be avoided if the Relation type is improved with a structure that maintains the association of relColumns and relFColumns
-          syns `sortAccordingTo` columns = sortOn (\(k, _) -> L.lookup k $ zip columns [0::Int ..]) syns
+          -- So we need to change the order of the SourceColumns to match the relColumns
+          -- TODO: This could be avoided if the Relation type is improved with a structure that maintains the association of relColumns and relFColumns
+          srcCols `sortAccordingTo` cols = sortOn (\(k, _) -> L.lookup k $ zip cols [0::Int ..]) srcCols

-          viewTableChild =
-            [ Relation (getView syns) (snd <$> syns `sortAccordingTo` relColumns)
-                       relFTable relFColumns
-                       Child Nothing Nothing Nothing
-            | syns <- colsSyns, syns `allSynsOf` relColumns ]
+          viewTableM2O =
+            [ Relation (getView srcCols) (snd <$> srcCols `sortAccordingTo` relColumns)
+                       relConstraint relFTable relFColumns
+                       M2O Nothing
+            | srcCols <- relSrcCols, srcCols `allSrcColsOf` relColumns ]

-          tableViewChild =
+          tableViewM2O =
            [ Relation relTable relColumns
-                       (getView fSyns) (snd <$> fSyns `sortAccordingTo` relFColumns)
-                       Child Nothing Nothing Nothing
-            | fSyns <- fColsSyns, fSyns `allSynsOf` relFColumns ]
+                       relConstraint
+                       (getView fSrcCols) (snd <$> fSrcCols `sortAccordingTo` relFColumns)
+                       M2O Nothing
+            | fSrcCols <- relFSrcCols, fSrcCols `allSrcColsOf` relFColumns ]

-          viewViewChild =
-            [ Relation (getView syns) (snd <$> syns `sortAccordingTo` relColumns)
-                       (getView fSyns) (snd <$> fSyns `sortAccordingTo` relFColumns)
-                       Child Nothing Nothing Nothing
-            | syns <- colsSyns, syns `allSynsOf` relColumns
-            , fSyns <- fColsSyns, fSyns `allSynsOf` relFColumns ]
+          viewViewM2O =
+            [ Relation (getView srcCols) (snd <$> srcCols `sortAccordingTo` relColumns)
+                       relConstraint
+                       (getView fSrcCols) (snd <$> fSrcCols `sortAccordingTo` relFColumns)
+                       M2O Nothing
+            | srcCols  <- relSrcCols, srcCols `allSrcColsOf` relColumns
+            , fSrcCols <- relFSrcCols, fSrcCols `allSrcColsOf` relFColumns ]

-      in viewTableChild ++ tableViewChild ++ viewViewChild
+      in viewTableM2O ++ tableViewM2O ++ viewViewM2O

    _ -> [])

-addParentRelations :: [Relation] -> [Relation]
-addParentRelations = concatMap (\rel@(Relation t c ft fc _ _ _ _) -> [rel, Relation ft fc t c Parent Nothing Nothing Nothing])
+addO2MRels :: [Relation] -> [Relation]
+addO2MRels = concatMap (\rel@(Relation t c cn ft fc _ _) -> [rel, Relation ft fc cn t c O2M Nothing])

-addManyToManyRelations :: [Relation] -> [Relation]
-addManyToManyRelations rels = rels ++ addMirrorRelation (mapMaybe link2Relation links)
+addM2MRels :: [Relation] -> [Relation]
+addM2MRels rels = rels ++ addMirrorRel (mapMaybe junction2Rel junctions)
  where
-    links = join $ map (combinations 2) $ filter (not . null) $ groupWith groupFn $ filter ( (==Child). relType) rels
+    junctions = join $ map (combinations 2) $ filter (not . null) $ groupWith groupFn $ filter ( (==M2O). relType) rels
    groupFn :: Relation -> Text
    groupFn Relation{relTable=Table{tableSchema=s, tableName=t}} = s <> "_" <> t
    -- Reference : https://wiki.haskell.org/99_questions/Solutions/26
@@ -346,19 +359,20 @@ addManyToManyRelations rels = rels ++ addMirrorRelation (mapMaybe link2Relation
    combinations 0 _  = [ [] ]
    combinations n xs = [ y:ys | y:xs' <- tails xs
                               , ys <- combinations (n-1) xs']
-    addMirrorRelation = concatMap (\rel@(Relation t c ft fc _ lt lc1 lc2) -> [rel, Relation ft fc t c Many lt lc2 lc1])
-    link2Relation [
-      Relation{relTable=lt, relColumns=lc1, relFTable=t,  relFColumns=c},
-      Relation{             relColumns=lc2, relFTable=ft, relFColumns=fc}
+    junction2Rel [
+      Relation{relTable=jt, relColumns=jc1, relConstraint=const1, relFTable=t,  relFColumns=c},
+      Relation{             relColumns=jc2, relConstraint=const2, relFTable=ft, relFColumns=fc}
      ]
-      | lc1 /= lc2 && length lc1 == 1 && length lc2 == 1 = Just $ Relation t c ft fc Many (Just lt) (Just lc1) (Just lc2)
+      | jc1 /= jc2 && length jc1 == 1 && length jc2 == 1 = Just $ Relation t c Nothing ft fc M2M (Just $ Junction jt const1 jc1 const2 jc2)
      | otherwise = Nothing
-    link2Relation _ = Nothing
+    junction2Rel _ = Nothing
+    addMirrorRel = concatMap (\rel@(Relation t c _ ft fc _ (Just (Junction jt const1 jc1 const2 jc2))) ->
+      [rel, Relation ft fc Nothing t c M2M (Just (Junction jt const2 jc2 const1 jc1))])

-addViewPrimaryKeys :: [Synonym] -> [PrimaryKey] -> [PrimaryKey]
-addViewPrimaryKeys syns = concatMap (\pk ->
+addViewPrimaryKeys :: [SourceColumn] -> [PrimaryKey] -> [PrimaryKey]
+addViewPrimaryKeys srcCols = concatMap (\pk ->
  let viewPks = (\(_, viewCol) -> PrimaryKey{pkTable=colTable viewCol, pkName=colName viewCol}) <$>
-                filter (\(col, _) -> colTable col == pkTable pk && colName col == pkName pk) syns in
+                filter (\(col, _) -> colTable col == pkTable pk && colName col == pkName pk) srcCols in
  pk : viewPks)

 allTables :: H.Statement () [Table]
@@ -370,13 +384,17 @@ allTables =
      n.nspname AS table_schema,
      c.relname AS table_name,
      NULL AS table_description,
-      c.relkind = 'r' OR (c.relkind IN ('v','f'))
-      AND (pg_relation_is_updatable(c.oid::regclass, FALSE) & 8) = 8
-      OR (EXISTS
-        ( SELECT 1
+      (
+        c.relkind IN ('r', 'v','f')
+        AND (pg_relation_is_updatable(c.oid::regclass, FALSE) & 8) = 8
+        OR EXISTS (
+          SELECT 1
          FROM pg_trigger
-          WHERE pg_trigger.tgrelid = c.oid
-          AND (pg_trigger.tgtype::integer & 69) = 69) ) AS insertable
+          WHERE
+            pg_trigger.tgrelid = c.oid
+            AND (pg_trigger.tgtype::integer & 69) = 69
+        )
+      ) AS insertable
    FROM pg_class c
    JOIN pg_namespace n ON n.oid = c.relnamespace
    WHERE c.relkind IN ('v','r','m','f')
@@ -384,9 +402,9 @@ allTables =
    GROUP BY table_schema, table_name, insertable
    ORDER BY table_schema, table_name |]

-allColumns :: [Table] -> H.Statement Schema [Column]
+allColumns :: [Table] -> H.Statement [Schema] [Column]
 allColumns tabs =
-  H.Statement sql (param HE.text) (decodeColumns tabs) True
+ H.Statement sql (arrayParam HE.text) (decodeColumns tabs) True
 where
  sql = [q|
    SELECT DISTINCT
@@ -403,9 +421,7 @@ allColumns tabs =
        info.column_default AS default_value,
        array_to_string(enum_info.vals, ',') AS enum
    FROM (
-        /*
-        -- CTE based on pg_catalog to get only Primary and Foreign key columns outside api schema
-        */
+        -- CTE based on pg_catalog to get PRIMARY/FOREIGN key and UNIQUE columns outside api schema
        WITH key_columns AS (
             SELECT
               r.oid AS r_oid,
@@ -420,11 +436,11 @@ allColumns tabs =
               pg_catalog.pg_class c,
               pg_catalog.pg_namespace n
             WHERE
-               r.contype IN ('f', 'p')
+               r.contype IN ('f', 'p', 'u')
               AND c.relkind IN ('r', 'v', 'f', 'm')
               AND r.conrelid = c.oid
               AND c.relnamespace = n.oid
-               AND n.nspname NOT IN ('pg_catalog', 'information_schema', $1)
+               AND n.nspname <> ANY (ARRAY['pg_catalog', 'information_schema'] || $1)
        ),
        /*
        -- CTE based on information_schema.columns
@@ -433,19 +449,16 @@ allColumns tabs =
        -- limit columns to the ones in the api schema or PK/FK columns
        */
        columns AS (
-            SELECT current_database()::information_schema.sql_identifier AS table_catalog,
-                nc.nspname::information_schema.sql_identifier AS table_schema,
-                c.relname::information_schema.sql_identifier AS table_name,
-                a.attname::information_schema.sql_identifier AS column_name,
-                d.description::information_schema.sql_identifier AS description,
-                a.attnum::information_schema.cardinal_number AS ordinal_position,
-                pg_get_expr(ad.adbin, ad.adrelid)::information_schema.character_data AS column_default,
+            SELECT
+                nc.nspname::name AS table_schema,
+                c.relname::name AS table_name,
+                a.attname::name AS column_name,
+                d.description AS description,
+                a.attnum::integer AS ordinal_position,
+                pg_get_expr(ad.adbin, ad.adrelid)::text AS column_default,
+                not (a.attnotnull OR t.typtype = 'd' AND t.typnotnull) AS is_nullable,
                    CASE
-                        WHEN a.attnotnull OR t.typtype = 'd'::"char" AND t.typnotnull THEN 'NO'::text
-                        ELSE 'YES'::text
-                    END::information_schema.yes_or_no AS is_nullable,
-                    CASE
-                        WHEN t.typtype = 'd'::"char" THEN
+                        WHEN t.typtype = 'd' THEN
                        CASE
                            WHEN bt.typelem <> 0::oid AND bt.typlen = (-1) THEN 'ARRAY'::text
                            WHEN nbt.nspname = 'pg_catalog'::name THEN format_type(t.typbasetype, NULL::integer)
@@ -457,77 +470,42 @@ allColumns tabs =
                            WHEN nt.nspname = 'pg_catalog'::name THEN format_type(a.atttypid, NULL::integer)
                            ELSE format_type(a.atttypid, a.atttypmod)
                        END
-                    END::information_schema.character_data AS data_type,
-                information_schema._pg_char_max_length(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS character_maximum_length,
-                information_schema._pg_char_octet_length(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS character_octet_length,
-                information_schema._pg_numeric_precision(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS numeric_precision,
-                information_schema._pg_numeric_precision_radix(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS numeric_precision_radix,
-                information_schema._pg_numeric_scale(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS numeric_scale,
-                information_schema._pg_datetime_precision(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.cardinal_number AS datetime_precision,
-                information_schema._pg_interval_type(information_schema._pg_truetypid(a.*, t.*), information_schema._pg_truetypmod(a.*, t.*))::information_schema.character_data AS interval_type,
-                NULL::integer::information_schema.cardinal_number AS interval_precision,
-                NULL::character varying::information_schema.sql_identifier AS character_set_catalog,
-                NULL::character varying::information_schema.sql_identifier AS character_set_schema,
-                NULL::character varying::information_schema.sql_identifier AS character_set_name,
-                    CASE
-                        WHEN nco.nspname IS NOT NULL THEN current_database()
-                        ELSE NULL::name
-                    END::information_schema.sql_identifier AS collation_catalog,
-                nco.nspname::information_schema.sql_identifier AS collation_schema,
-                co.collname::information_schema.sql_identifier AS collation_name,
-                    CASE
-                        WHEN t.typtype = 'd'::"char" THEN current_database()
-                        ELSE NULL::name
-                    END::information_schema.sql_identifier AS domain_catalog,
-                    CASE
-                        WHEN t.typtype = 'd'::"char" THEN nt.nspname
-                        ELSE NULL::name
-                    END::information_schema.sql_identifier AS domain_schema,
-                    CASE
-                        WHEN t.typtype = 'd'::"char" THEN t.typname
-                        ELSE NULL::name
-                    END::information_schema.sql_identifier AS domain_name,
-                current_database()::information_schema.sql_identifier AS udt_catalog,
-                COALESCE(nbt.nspname, nt.nspname)::information_schema.sql_identifier AS udt_schema,
-                COALESCE(bt.typname, t.typname)::information_schema.sql_identifier AS udt_name,
-                NULL::character varying::information_schema.sql_identifier AS scope_catalog,
-                NULL::character varying::information_schema.sql_identifier AS scope_schema,
-                NULL::character varying::information_schema.sql_identifier AS scope_name,
-                NULL::integer::information_schema.cardinal_number AS maximum_cardinality,
-                a.attnum::information_schema.sql_identifier AS dtd_identifier,
-                'NO'::character varying::information_schema.yes_or_no AS is_self_referencing,
-                'NO'::character varying::information_schema.yes_or_no AS is_identity,
-                NULL::character varying::information_schema.character_data AS identity_generation,
-                NULL::character varying::information_schema.character_data AS identity_start,
-                NULL::character varying::information_schema.character_data AS identity_increment,
-                NULL::character varying::information_schema.character_data AS identity_maximum,
-                NULL::character varying::information_schema.character_data AS identity_minimum,
-                NULL::character varying::information_schema.yes_or_no AS identity_cycle,
-                'NEVER'::character varying::information_schema.character_data AS is_generated,
-                NULL::character varying::information_schema.character_data AS generation_expression,
-                CASE
-                    WHEN c.relkind = 'r'::"char" OR (c.relkind = ANY (ARRAY['v'::"char", 'f'::"char"])) AND pg_column_is_updatable(c.oid::regclass, a.attnum, false) THEN 'YES'::text
-                    ELSE 'NO'::text
-                END::information_schema.yes_or_no AS is_updatable
+                    END::text AS data_type,
+                information_schema._pg_char_max_length(
+                    information_schema._pg_truetypid(a.*, t.*),
+                    information_schema._pg_truetypmod(a.*, t.*)
+                )::integer AS character_maximum_length,
+                information_schema._pg_numeric_precision(
+                    information_schema._pg_truetypid(a.*, t.*),
+                    information_schema._pg_truetypmod(a.*, t.*)
+                )::integer AS numeric_precision,
+                COALESCE(bt.typname, t.typname)::name AS udt_name,
+                (
+                    c.relkind in ('r', 'v', 'f')
+                    AND pg_column_is_updatable(c.oid::regclass, a.attnum, false)
+                )::bool is_updatable
            FROM pg_attribute a
-               LEFT JOIN key_columns kc ON kc.conkey = a.attnum AND kc.c_oid = a.attrelid
-               LEFT JOIN pg_catalog.pg_description AS d ON d.objoid = a.attrelid and d.objsubid = a.attnum
-               LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
-               JOIN (pg_class c
-               JOIN pg_namespace nc ON c.relnamespace = nc.oid) ON a.attrelid = c.oid
-               JOIN (pg_type t
-               JOIN pg_namespace nt ON t.typnamespace = nt.oid) ON a.atttypid = t.oid
-               LEFT JOIN (pg_type bt
-               JOIN pg_namespace nbt ON bt.typnamespace = nbt.oid) ON t.typtype = 'd'::"char" AND t.typbasetype = bt.oid
-               LEFT JOIN (pg_collation co
-               JOIN pg_namespace nco ON co.collnamespace = nco.oid) ON a.attcollation = co.oid AND (nco.nspname <> 'pg_catalog'::name OR co.collname <> 'default'::name)
+                LEFT JOIN key_columns kc
+                    ON kc.conkey = a.attnum AND kc.c_oid = a.attrelid
+                LEFT JOIN pg_catalog.pg_description AS d
+                    ON d.objoid = a.attrelid and d.objsubid = a.attnum
+                LEFT JOIN pg_attrdef ad
+                    ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
+                JOIN (pg_class c JOIN pg_namespace nc ON c.relnamespace = nc.oid)
+                    ON a.attrelid = c.oid
+                JOIN (pg_type t JOIN pg_namespace nt ON t.typnamespace = nt.oid)
+                    ON a.atttypid = t.oid
+                LEFT JOIN (pg_type bt JOIN pg_namespace nbt ON bt.typnamespace = nbt.oid)
+                    ON t.typtype = 'd' AND t.typbasetype = bt.oid
+                LEFT JOIN (pg_collation co JOIN pg_namespace nco ON co.collnamespace = nco.oid)
+                    ON a.attcollation = co.oid AND (nco.nspname <> 'pg_catalog'::name OR co.collname <> 'default'::name)
            WHERE
                NOT pg_is_other_temp_schema(nc.oid)
                AND a.attnum > 0
                AND NOT a.attisdropped
-                AND (c.relkind = ANY (ARRAY['r'::"char", 'v'::"char", 'f'::"char", 'm'::"char"]))
-                AND (nc.nspname = $1 OR kc.r_oid IS NOT NULL) /*--filter only columns that are FK/PK or in the api schema */
-              /*--AND (pg_has_role(c.relowner, 'USAGE'::text) OR has_column_privilege(c.oid, a.attnum, 'SELECT, INSERT, UPDATE, REFERENCES'::text))*/
+                AND c.relkind in ('r', 'v', 'f', 'm')
+                -- Filter only columns that are FK/PK or in the api schema:
+                AND (nc.nspname = ANY ($1) OR kc.r_oid IS NOT NULL)
        )
        SELECT
            table_schema,
@@ -542,7 +520,6 @@ allColumns tabs =
            numeric_precision,
            column_default,
            udt_name
-        /*-- FROM information_schema.columns*/
        FROM columns
        WHERE table_schema NOT IN ('pg_catalog', 'information_schema')
    ) AS info
@@ -571,39 +548,36 @@ columnFromRow tabs (s, t, n, desc, pos, nul, typ, u, l, p, d, e) = buildColumn <
    parseEnum :: Maybe Text -> [Text]
    parseEnum = maybe [] (split (==','))

-allChildRelations :: [Table] -> [Column] -> H.Statement () [Relation]
-allChildRelations tabs cols =
-  H.Statement sql HE.noParams (decodeRelations tabs cols) True
+allM2ORels :: [Table] -> [Column] -> H.Statement () [Relation]
+allM2ORels tabs cols =
+  H.Statement sql HE.noParams (decodeRels tabs cols) True
 where
  sql = [q|
    SELECT ns1.nspname AS table_schema,
           tab.relname AS table_name,
+           conname     AS constraint_name,
           column_info.cols AS columns,
           ns2.nspname AS foreign_table_schema,
           other.relname AS foreign_table_name,
           column_info.refs AS foreign_columns
    FROM pg_constraint,
-       LATERAL (SELECT array_agg(cols.attname) AS cols,
-                       array_agg(cols.attnum)  AS nums,
-                       array_agg(refs.attname) AS refs
-                  FROM ( SELECT unnest(conkey) AS col, unnest(confkey) AS ref) k,
-                       LATERAL (SELECT * FROM pg_attribute
-                                 WHERE attrelid = conrelid AND attnum = col)
-                            AS cols,
-                       LATERAL (SELECT * FROM pg_attribute
-                                 WHERE attrelid = confrelid AND attnum = ref)
-                            AS refs)
-            AS column_info,
-       LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = connamespace) AS ns1,
-       LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = conrelid) AS tab,
-       LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = confrelid) AS other,
-       LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = other.relnamespace) AS ns2
+    LATERAL (
+      SELECT array_agg(cols.attname) AS cols,
+                    array_agg(cols.attnum)  AS nums,
+                    array_agg(refs.attname) AS refs
+      FROM ( SELECT unnest(conkey) AS col, unnest(confkey) AS ref) k,
+      LATERAL (SELECT * FROM pg_attribute WHERE attrelid = conrelid AND attnum = col) AS cols,
+      LATERAL (SELECT * FROM pg_attribute WHERE attrelid = confrelid AND attnum = ref) AS refs) AS column_info,
+    LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = connamespace) AS ns1,
+    LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = conrelid) AS tab,
+    LATERAL (SELECT * FROM pg_class WHERE pg_class.oid = confrelid) AS other,
+    LATERAL (SELECT * FROM pg_namespace WHERE pg_namespace.oid = other.relnamespace) AS ns2
    WHERE confrelid != 0
    ORDER BY (conrelid, column_info.nums) |]

-relationFromRow :: [Table] -> [Column] -> (Text, Text, [Text], Text, Text, [Text]) -> Maybe Relation
-relationFromRow allTabs allCols (rs, rt, rcs, frs, frt, frcs) =
-  Relation <$> table <*> cols <*> tableF <*> colsF <*> pure Child <*> pure Nothing <*> pure Nothing <*> pure Nothing
+relFromRow :: [Table] -> [Column] -> (Text, Text, Text, [Text], Text, Text, [Text]) -> Maybe Relation
+relFromRow allTabs allCols (rs, rt, cn, rcs, frs, frt, frcs) =
+  Relation <$> table <*> cols <*> pure (Just cn) <*> tableF <*> colsF <*> pure M2O <*> pure Nothing
  where
    findTable s t = find (\tbl -> tableSchema tbl == s && tableName tbl == t) allTabs
    findCol s t c = find (\col -> tableSchema (colTable col) == s && tableName (colTable col) == t && colName col == c) allCols
@@ -617,69 +591,36 @@ allPrimaryKeys tabs =
  H.Statement sql HE.noParams (decodePks tabs) True
 where
  sql = [q|
-    /*
    -- CTE to replace information_schema.table_constraints to remove owner limit
-    */
    WITH tc AS (
-        SELECT current_database()::information_schema.sql_identifier AS constraint_catalog,
-            nc.nspname::information_schema.sql_identifier AS constraint_schema,
-            c.conname::information_schema.sql_identifier AS constraint_name,
-            current_database()::information_schema.sql_identifier AS table_catalog,
-            nr.nspname::information_schema.sql_identifier AS table_schema,
-            r.relname::information_schema.sql_identifier AS table_name,
-                CASE c.contype
-                    WHEN 'c'::"char" THEN 'CHECK'::text
-                    WHEN 'f'::"char" THEN 'FOREIGN KEY'::text
-                    WHEN 'p'::"char" THEN 'PRIMARY KEY'::text
-                    WHEN 'u'::"char" THEN 'UNIQUE'::text
-                    ELSE NULL::text
-                END::information_schema.character_data AS constraint_type,
-                CASE
-                    WHEN c.condeferrable THEN 'YES'::text
-                    ELSE 'NO'::text
-                END::information_schema.yes_or_no AS is_deferrable,
-                CASE
-                    WHEN c.condeferred THEN 'YES'::text
-                    ELSE 'NO'::text
-                END::information_schema.yes_or_no AS initially_deferred
+        SELECT
+            c.conname::name AS constraint_name,
+            nr.nspname::name AS table_schema,
+            r.relname::name AS table_name
        FROM pg_namespace nc,
            pg_namespace nr,
            pg_constraint c,
            pg_class r
-        WHERE nc.oid = c.connamespace AND nr.oid = r.relnamespace AND c.conrelid = r.oid AND (c.contype <> ALL (ARRAY['t'::"char", 'x'::"char"])) AND r.relkind = 'r'::"char" AND NOT pg_is_other_temp_schema(nr.oid)
-        /*--AND (pg_has_role(r.relowner, 'USAGE'::text) OR has_table_privilege(r.oid, 'INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, TRIGGER'::text) OR has_any_column_privilege(r.oid, 'INSERT, UPDATE, REFERENCES'::text))*/
-        UNION ALL
-        SELECT current_database()::information_schema.sql_identifier AS constraint_catalog,
-            nr.nspname::information_schema.sql_identifier AS constraint_schema,
-            (((((nr.oid::text || '_'::text) || r.oid::text) || '_'::text) || a.attnum::text) || '_not_null'::text)::information_schema.sql_identifier AS constraint_name,
-            current_database()::information_schema.sql_identifier AS table_catalog,
-            nr.nspname::information_schema.sql_identifier AS table_schema,
-            r.relname::information_schema.sql_identifier AS table_name,
-            'CHECK'::character varying::information_schema.character_data AS constraint_type,
-            'NO'::character varying::information_schema.yes_or_no AS is_deferrable,
-            'NO'::character varying::information_schema.yes_or_no AS initially_deferred
-        FROM pg_namespace nr,
-            pg_class r,
-            pg_attribute a
-        WHERE nr.oid = r.relnamespace AND r.oid = a.attrelid AND a.attnotnull AND a.attnum > 0 AND NOT a.attisdropped AND r.relkind = 'r'::"char" AND NOT pg_is_other_temp_schema(nr.oid)
-        /*--AND (pg_has_role(r.relowner, 'USAGE'::text) OR has_table_privilege(r.oid, 'INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, TRIGGER'::text) OR has_any_column_privilege(r.oid, 'INSERT, UPDATE, REFERENCES'::text))*/
+        WHERE
+            nc.oid = c.connamespace
+            AND nr.oid = r.relnamespace
+            AND c.conrelid = r.oid
+            AND r.relkind = 'r'
+            AND NOT pg_is_other_temp_schema(nr.oid)
+            AND c.contype = 'p'
    ),
-    /*
    -- CTE to replace information_schema.key_column_usage to remove owner limit
-    */
    kc AS (
-        SELECT current_database()::information_schema.sql_identifier AS constraint_catalog,
-            ss.nc_nspname::information_schema.sql_identifier AS constraint_schema,
-            ss.conname::information_schema.sql_identifier AS constraint_name,
-            current_database()::information_schema.sql_identifier AS table_catalog,
-            ss.nr_nspname::information_schema.sql_identifier AS table_schema,
-            ss.relname::information_schema.sql_identifier AS table_name,
-            a.attname::information_schema.sql_identifier AS column_name,
-            (ss.x).n::information_schema.cardinal_number AS ordinal_position,
-                CASE
-                    WHEN ss.contype = 'f'::"char" THEN information_schema._pg_index_position(ss.conindid, ss.confkey[(ss.x).n])
-                    ELSE NULL::integer
-                END::information_schema.cardinal_number AS position_in_unique_constraint
+        SELECT
+            ss.conname::name AS constraint_name,
+            ss.nr_nspname::name AS table_schema,
+            ss.relname::name AS table_name,
+            a.attname::name AS column_name,
+            (ss.x).n::integer AS ordinal_position,
+            CASE
+                WHEN ss.contype = 'f' THEN information_schema._pg_index_position(ss.conindid, ss.confkey[(ss.x).n])
+                ELSE NULL::integer
+            END::integer AS position_in_unique_constraint
        FROM pg_attribute a,
            ( SELECT r.oid AS roid,
                r.relname,
@@ -691,28 +632,31 @@ allPrimaryKeys tabs =
                c.contype,
                c.conindid,
                c.confkey,
-                c.confrelid,
                information_schema._pg_expandarray(c.conkey) AS x
               FROM pg_namespace nr,
                pg_class r,
                pg_namespace nc,
                pg_constraint c
-              WHERE nr.oid = r.relnamespace AND r.oid = c.conrelid AND nc.oid = c.connamespace AND (c.contype = ANY (ARRAY['p'::"char", 'u'::"char", 'f'::"char"])) AND r.relkind = 'r'::"char" AND NOT pg_is_other_temp_schema(nr.oid)) ss
-        WHERE ss.roid = a.attrelid AND a.attnum = (ss.x).x AND NOT a.attisdropped
-        /*--AND (pg_has_role(ss.relowner, 'USAGE'::text) OR has_column_privilege(ss.roid, a.attnum, 'SELECT, INSERT, UPDATE, REFERENCES'::text))*/
+              WHERE
+                nr.oid = r.relnamespace
+                AND r.oid = c.conrelid
+                AND nc.oid = c.connamespace
+                AND c.contype in ('p', 'u', 'f')
+                AND r.relkind = 'r'
+                AND NOT pg_is_other_temp_schema(nr.oid)
+            ) ss
+        WHERE
+          ss.roid = a.attrelid
+          AND a.attnum = (ss.x).x
+          AND NOT a.attisdropped
    )
    SELECT
        kc.table_schema,
        kc.table_name,
        kc.column_name
    FROM
-        /*
-        --information_schema.table_constraints tc,
-        --information_schema.key_column_usage kc
-        */
        tc, kc
    WHERE
-        tc.constraint_type = 'PRIMARY KEY' AND
        kc.table_name = tc.table_name AND
        kc.table_schema = tc.table_schema AND
        kc.constraint_name = tc.constraint_name AND
@@ -722,9 +666,9 @@ pkFromRow :: [Table] -> (Schema, Text, Text) -> Maybe PrimaryKey
 pkFromRow tabs (s, t, n) = PrimaryKey <$> table <*> pure n
  where table = find (\tbl -> tableSchema tbl == s && tableName tbl == t) tabs

-allSynonyms :: [Column] -> PgVersion -> H.Statement Schema [Synonym]
-allSynonyms cols pgVer =
-  H.Statement sql (param HE.text) (decodeSynonyms cols) True
+allSourceColumns :: [Column] -> PgVersion -> H.Statement [Schema] [SourceColumn]
+allSourceColumns cols pgVer =
+  H.Statement sql (arrayParam HE.text) (decodeSourceColumns cols) True
  -- query explanation at https://gist.github.com/steve-chavez/7ee0e6590cddafb532e5f00c46275569
  where
    subselectRegex :: Text
@@ -743,7 +687,7 @@ allSynonyms cols pgVer =
        from pg_class c
        join pg_namespace n on n.oid = c.relnamespace
        join pg_rewrite r on r.ev_class = c.oid
-        where (c.relkind in ('v', 'm')) and n.nspname = $1
+        where c.relkind in ('v', 'm') and n.nspname = ANY ($1)
      ),
      removed_subselects as(
        select
@@ -791,13 +735,6 @@ allSynonyms cols pgVer =
      where resorigtbl <> '0'
      order by view_schema, view_name, view_colum_name; |]

-synonymFromRow :: [Column] -> (Text,Text,Text,Text,Text,Text) -> Maybe Synonym
-synonymFromRow allCols (s1,t1,c1,s2,t2,c2) = (,) <$> col1 <*> col2
-  where
-    col1 = findCol s1 t1 c1
-    col2 = findCol s2 t2 c2
-    findCol s t c = find (\col -> (tableSchema . colTable) col == s && (tableName . colTable) col == t && colName col == c) allCols
-
 getPgVersion :: H.Session PgVersion
 getPgVersion = H.statement () $ H.Statement sql HE.noParams versionRow False
  where
@@ -16,19 +16,19 @@ module PostgREST.Error (
 ) where

 import qualified Data.Aeson                as JSON
+import qualified Data.Text                 as T
 import qualified Hasql.Pool                as P
 import qualified Hasql.Session             as H
 import qualified Network.HTTP.Types.Status as HT

 import Data.Aeson  ((.=))
-import Data.Text   (unwords)
 import Network.Wai (Response, responseLBS)
-import Text.Read   (readMaybe)

 import Network.HTTP.Types.Header

 import PostgREST.Types
-import Protolude
+import Protolude       hiding (toS)
+import Protolude.Conv  (toS)


 class (JSON.ToJSON a) => PgrstError a where
@@ -48,8 +48,10 @@ data ApiRequestError
  | InvalidRange
  | InvalidBody ByteString
  | ParseRequestError Text Text
-  | NoRelationBetween Text Text
+  | NoRelBetween Text Text
+  | AmbiguousRelBetween Text Text [Relation]
  | InvalidFilters
+  | UnacceptableSchema [Text]
  | UnknownRelation                -- Unreachable?
  | UnsupportedVerb                -- Unreachable?
  deriving (Show, Eq)
@@ -62,7 +64,9 @@ instance PgrstError ApiRequestError where
  status UnknownRelation         = HT.status404
  status ActionInappropriate     = HT.status405
  status (ParseRequestError _ _) = HT.status400
-  status (NoRelationBetween _ _) = HT.status400
+  status (NoRelBetween _ _)      = HT.status400
+  status AmbiguousRelBetween{}   = HT.status300
+  status (UnacceptableSchema _)  = HT.status406

  headers _ = [toHeader CTApplicationJSON]

@@ -77,13 +81,39 @@ instance JSON.ToJSON ApiRequestError where
    "message" .= ("HTTP Range error" :: Text)]
  toJSON UnknownRelation = JSON.object [
    "message" .= ("Unknown relation" :: Text)]
-  toJSON (NoRelationBetween parent child) = JSON.object [
-    "message" .= ("Could not find foreign keys between these entities, No relation found between " <> parent <> " and " <> child :: Text)]
+  toJSON (NoRelBetween parent child) = JSON.object [
+    "message" .= ("Could not find foreign keys between these entities. No relationship found between " <> parent <> " and " <> child :: Text)]
+  toJSON (AmbiguousRelBetween parent child rels) = JSON.object [
+    "hint"    .= ("By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)" :: Text),
+    "message" .= ("More than one relationship was found for " <> parent <> " and " <> child :: Text),
+    "details" .= (compressedRel <$> rels) ]
  toJSON UnsupportedVerb = JSON.object [
    "message" .= ("Unsupported HTTP verb" :: Text)]
  toJSON InvalidFilters = JSON.object [
    "message" .= ("Filters must include all and only primary key columns with 'eq' operators" :: Text)]
+  toJSON (UnacceptableSchema schemas) = JSON.object [
+    "message" .= ("The schema must be one of the following: " <> T.intercalate ", " schemas)]

+compressedRel :: Relation -> JSON.Value
+compressedRel rel =
+  let
+    fmtTbl tbl = tableSchema tbl <> "." <> tableName tbl
+    fmtEls els = "[" <> T.intercalate ", " els <> "]"
+  in
+  JSON.object $ [
+    "origin"      .= fmtTbl (relTable rel)
+  , "target"      .= fmtTbl (relFTable rel)
+  , "cardinality" .= (show $ relType rel :: Text)
+  ] ++
+  case (relType rel, relJunction rel, relConstraint rel) of
+    (M2M, Just (Junction jt (Just const1) _ (Just const2) _), _) -> [
+      "relationship" .= (fmtTbl jt <> fmtEls [const1] <> fmtEls [const2])
+      ]
+    (_, _, Just relCon) -> [
+      "relationship" .= (relCon <> fmtEls (colName <$> relColumns rel) <> fmtEls (colName <$> relFColumns rel))
+      ]
+    (_, _, _) ->
+      mempty

 data PgError = PgError Authenticated P.UsageError
 type Authenticated = Bool
@@ -193,10 +223,8 @@ data SimpleError
  = GucHeadersError
  | BinaryFieldError ContentType
  | ConnectionLostError
-  | PutSingletonError
  | PutMatchingPkError
  | PutRangeNotAllowedError
-  | PutPayloadIncompleteError
  | JwtTokenMissing
  | JwtTokenInvalid Text
  | SingularityError Integer
@@ -204,17 +232,15 @@ data SimpleError
  deriving (Show, Eq)

 instance PgrstError SimpleError where
-  status GucHeadersError           = HT.status500
-  status (BinaryFieldError _)      = HT.status406
-  status ConnectionLostError       = HT.status503
-  status PutSingletonError         = HT.status400
-  status PutMatchingPkError        = HT.status400
-  status PutRangeNotAllowedError   = HT.status400
-  status PutPayloadIncompleteError = HT.status400
-  status JwtTokenMissing           = HT.status500
-  status (JwtTokenInvalid _)       = HT.unauthorized401
-  status (SingularityError _)      = HT.status406
-  status (ContentTypeError _)      = HT.status415
+  status GucHeadersError         = HT.status500
+  status (BinaryFieldError _)    = HT.status406
+  status ConnectionLostError     = HT.status503
+  status PutMatchingPkError      = HT.status400
+  status PutRangeNotAllowedError = HT.status400
+  status JwtTokenMissing         = HT.status500
+  status (JwtTokenInvalid _)     = HT.unauthorized401
+  status (SingularityError _)    = HT.status406
+  status (ContentTypeError _)    = HT.status415

  headers (SingularityError _)     = [toHeader CTSingularJSON]
  headers (JwtTokenInvalid m)      = [toHeader CTApplicationJSON, invalidTokenHeader m]
@@ -224,16 +250,12 @@ instance JSON.ToJSON SimpleError where
  toJSON GucHeadersError           = JSON.object [
    "message" .= ("response.headers guc must be a JSON array composed of objects with a single key and a string value" :: Text)]
  toJSON (BinaryFieldError ct)          = JSON.object [
-    "message" .= ((toS (toMime ct) <> " requested but a single column was not selected") :: Text)]
+    "message" .= ((toS (toMime ct) <> " requested but more than one column was selected") :: Text)]
  toJSON ConnectionLostError       = JSON.object [
    "message" .= ("Database connection lost, retrying the connection." :: Text)]

-  toJSON PutSingletonError         = JSON.object [
-    "message" .= ("PUT payload must contain a single row" :: Text)]
  toJSON PutRangeNotAllowedError   = JSON.object [
    "message" .= ("Range header and limit/offset querystring parameters are not allowed for PUT" :: Text)]
-  toJSON PutPayloadIncompleteError = JSON.object [
-    "message" .= ("You must specify all columns in the payload when using PUT" :: Text)]
  toJSON PutMatchingPkError        = JSON.object [
    "message" .= ("Payload values do not match URL in primary key column(s)" :: Text)]

@@ -241,7 +263,7 @@ instance JSON.ToJSON SimpleError where
    "message" .= ("None of these Content-Types are available: " <> (toS . intercalate ", " . map toS) cts :: Text)]
  toJSON (SingularityError n)      = JSON.object [
    "message" .= ("JSON object requested, multiple (or no) rows returned" :: Text),
-    "details" .= unwords ["Results contain", show n, "rows,", toS (toMime CTSingularJSON), "requires 1 row"]]
+    "details" .= T.unwords ["Results contain", show n, "rows,", toS (toMime CTSingularJSON), "requires 1 row"]]

  toJSON JwtTokenMissing           = JSON.object [
    "message" .= ("Server lacks JWT secret" :: Text)]
@@ -250,7 +272,7 @@ instance JSON.ToJSON SimpleError where

 invalidTokenHeader :: Text -> Header
 invalidTokenHeader m =
-  ("WWW-Authenticate", "Bearer error=\"invalid_token\", " <> "error_description=" <> show m)
+  ("WWW-Authenticate", "Bearer error=\"invalid_token\", " <> "error_description=" <> encodeUtf8 (show m))

 singularityError :: (Integral a) => a -> SimpleError
 singularityError = SingularityError . toInteger
@@ -10,6 +10,8 @@ module PostgREST.Middleware where

 import qualified Data.Aeson          as JSON
 import qualified Data.HashMap.Strict as M
+import           Data.Scientific     (FPFormat (..), formatScientific,
+                                      isInteger)
 import qualified Hasql.Transaction   as H

 import Network.Wai                   (Application, Response)
@@ -24,9 +26,9 @@ import PostgREST.Auth         (JWTAttempt (..))
 import PostgREST.Config       (AppConfig (..), corsPolicy)
 import PostgREST.Error        (SimpleError (JwtTokenInvalid, JwtTokenMissing),
                               errorResponseFor)
-import PostgREST.QueryBuilder (pgFmtSetLocal, pgFmtSetLocalSearchPath,
-                               unquoted)
-import Protolude
+import PostgREST.QueryBuilder (setLocalQuery, setLocalSearchPathQuery)
+import Protolude              hiding (head, toS)
+import Protolude.Conv         (toS)

 runWithClaims :: AppConfig -> JWTAttempt ->
                 (ApiRequest -> H.Transaction Response) ->
@@ -37,17 +39,19 @@ runWithClaims conf eClaims app req =
    JWTInvalid JWTExpired -> return . errorResponseFor . JwtTokenInvalid $ "JWT expired"
    JWTInvalid e          -> return . errorResponseFor . JwtTokenInvalid . show $ e
    JWTClaims claims      -> do
-      H.sql $ toS . mconcat $ setSearchPathSql : setRoleSql ++ claimsSql ++ headersSql ++ cookiesSql ++ appSettingsSql
+      H.sql $ toS . mconcat $ setSearchPathSql : setRoleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql
      mapM_ H.sql customReqCheck
      app req
      where
-        headersSql = pgFmtSetLocal "request.header." <$> iHeaders req
-        cookiesSql = pgFmtSetLocal "request.cookie." <$> iCookies req
-        claimsSql = pgFmtSetLocal "request.jwt.claim." <$> [(c,unquoted v) | (c,v) <- M.toList claimsWithRole]
-        appSettingsSql = pgFmtSetLocal mempty <$> configSettings conf
+        methodSql = setLocalQuery mempty ("request.method", toS $ iMethod req)
+        pathSql = setLocalQuery mempty ("request.path", toS $ iPath req)
+        headersSql = setLocalQuery "request.header." <$> iHeaders req
+        cookiesSql = setLocalQuery "request.cookie." <$> iCookies req
+        claimsSql = setLocalQuery "request.jwt.claim." <$> [(c,unquoted v) | (c,v) <- M.toList claimsWithRole]
+        appSettingsSql = setLocalQuery mempty <$> configSettings conf
        setRoleSql = maybeToList $ (\x ->
-          pgFmtSetLocal mempty ("role", unquoted x)) <$> M.lookup "role" claimsWithRole
-        setSearchPathSql = pgFmtSetLocalSearchPath $ configSchema conf : configExtraSearchPath conf
+          setLocalQuery mempty ("role", unquoted x)) <$> M.lookup "role" claimsWithRole
+        setSearchPathSql = setLocalSearchPathQuery (iSchema req : configExtraSearchPath conf)
        -- role claim defaults to anon if not specified in jwt
        claimsWithRole = M.union claims (M.singleton "role" anon)
        anon = JSON.String . toS $ configAnonRole conf
@@ -58,3 +62,10 @@ defaultMiddle =
    gzip def
  . cors corsPolicy
  . staticPolicy (only [("favicon.ico", "static/favicon.ico")])
+
+unquoted :: JSON.Value -> Text
+unquoted (JSON.String t) = t
+unquoted (JSON.Number n) =
+  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
+unquoted (JSON.Bool b) = show b
+unquoted v = toS $ JSON.encode v
@@ -10,7 +10,7 @@ module PostgREST.OpenAPI (
 , pickProxy
 ) where

-import qualified Data.Set as Set
+import qualified Data.HashSet.InsOrd as Set

 import Control.Arrow              ((&&&))
 import Data.Aeson                 (decode, encode)
@@ -32,7 +32,8 @@ import PostgREST.Types      (Column (..), ForeignKey (..), PgArg (..),
                             PrimaryKey (..), ProcDescription (..),
                             Proxy (..), Table (..), toMime)
 import Protolude            hiding (Proxy, dropWhile, get,
-                             intercalate, (&))
+                             intercalate, toLower, toS, (&))
+import Protolude.Conv       (toS)

 makeMimeList :: [ContentType] -> MimeList
 makeMimeList cs = MimeList $ map (fromString . toS . toMime) cs
@@ -55,7 +56,7 @@ makeTableDef pks (t, cs, _) =
  let tn = tableName t in
      (tn, (mempty :: Schema)
        & description .~ tableDescription t
-        & type_ .~ SwaggerObject
+        & type_ ?~ SwaggerObject
        & properties .~ fromList (map (makeProperty pks) cs)
        & required .~ map colName (filter (not . colNullable) cs))

@@ -84,13 +85,13 @@ makeProperty pks c = (colName c, Inline s)
        & enum_ .~ e
        & format ?~ colType c
        & maxLength .~ (fromIntegral <$> colMaxLen c)
-        & type_ .~ toSwaggerType (colType c)
+        & type_ ?~ toSwaggerType (colType c)

 makeProcSchema :: ProcDescription -> Schema
 makeProcSchema pd =
  (mempty :: Schema)
  & description .~ pdDescription pd
-  & type_ .~ SwaggerObject
+  & type_ ?~ SwaggerObject
  & properties .~ fromList (map makeProcProperty (pdArgs pd))
  & required .~ map pgaName (filter pgaReq (pdArgs pd))

@@ -98,7 +99,7 @@ makeProcProperty :: PgArg -> (Text, Referenced Schema)
 makeProcProperty (PgArg n t _) = (n, Inline s)
  where
    s = (mempty :: Schema)
-          & type_ .~ toSwaggerType t
+          & type_ ?~ toSwaggerType t
          & format ?~ t

 makePreferParam :: [Text] -> Param
@@ -109,7 +110,7 @@ makePreferParam ts =
  & required    ?~ False
  & schema .~ ParamOther ((mempty :: ParamOtherSchema)
    & in_ .~ ParamHeader
-    & type_ .~ SwaggerString
+    & type_ ?~ SwaggerString
    & enum_ .~ decode (encode ts))

 makeProcParam :: ProcDescription -> [Referenced Param]
@@ -117,7 +118,7 @@ makeProcParam pd =
  [ Inline $ (mempty :: Param)
    & name     .~ "args"
    & required ?~ True
-    & schema   .~ (ParamBody $ Inline $ makeProcSchema pd)
+    & schema   .~ ParamBody (Inline $ makeProcSchema pd)
  , Ref $ Reference "preferParams"
  ]

@@ -132,28 +133,35 @@ makeParamDefs ti =
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
+  , ("on_conflict", (mempty :: Param)
+      & name        .~ "on_conflict"
+      & description ?~ "On Conflict"
+      & required    ?~ False
+      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
+        & in_ .~ ParamQuery
+        & type_ ?~ SwaggerString))
  , ("order", (mempty :: Param)
      & name        .~ "order"
      & description ?~ "Ordering"
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
  , ("range", (mempty :: Param)
      & name        .~ "Range"
      & description ?~ "Limiting and Pagination"
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamHeader
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
  , ("rangeUnit", (mempty :: Param)
      & name        .~ "Range-Unit"
      & description ?~ "Limiting and Pagination"
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamHeader
-        & type_ .~ SwaggerString
+        & type_ ?~ SwaggerString
        & default_ .~ decode "\"items\""))
  , ("offset", (mempty :: Param)
      & name        .~ "offset"
@@ -161,14 +169,14 @@ makeParamDefs ti =
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
  , ("limit", (mempty :: Param)
      & name        .~ "limit"
      & description ?~ "Limiting and Pagination"
      & required    ?~ False
      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
        & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
  ]
  <> concat [ makeObjectBody (tableName t) : makeRowFilters (tableName t) cs
            | (t, cs, _) <- ti
@@ -190,7 +198,7 @@ makeRowFilter tn c =
    & required ?~ False
    & schema .~ ParamOther ((mempty :: ParamOtherSchema)
      & in_ .~ ParamQuery
-      & type_ .~ SwaggerString
+      & type_ ?~ SwaggerString
      & format ?~ colType c))

 makeRowFilters :: Text -> [Column] -> [(Text, Param)]
@@ -213,12 +221,12 @@ makePathItem (t, cs, _) = ("/" ++ unpack tn, p $ tableInsertable t)
      & at 200 ?~ Inline ((mempty :: Response)
        & description .~ "OK"
        & schema ?~ Inline (mempty
-          & type_ .~ SwaggerArray
-          & items ?~ (SwaggerItemsObject $ Ref $ Reference $ tableName t)
+          & type_ ?~ SwaggerArray
+          & items ?~ SwaggerItemsObject (Ref $ Reference $ tableName t)
        )
      )
    postOp = tOp
-      & parameters .~ map ref ["body." <> tn, "preferReturn"]
+      & parameters .~ map ref ["body." <> tn, "select", "preferReturn"]
      & at 201 ?~ "Created"
    patchOp = tOp
      & parameters .~ map ref (rs <> ["body." <> tn, "preferReturn"])
@@ -9,10 +9,8 @@ module PostgREST.Parsers where
 import qualified Data.HashMap.Strict as M
 import qualified Data.Set            as S

-import Control.Monad           ((>>))
 import Data.Either.Combinators (mapLeft)
 import Data.Foldable           (foldl1)
-import Data.Functor            (($>))
 import Data.List               (init, last)
 import Data.Text               (intercalate, replace, strip)
 import Text.Read               (read)
@@ -24,12 +22,18 @@ import Text.ParserCombinators.Parsec hiding (many, (<|>))
 import PostgREST.Error      (ApiRequestError (ParseRequestError))
 import PostgREST.RangeQuery (NonnegRange)
 import PostgREST.Types
-import Protolude            hiding (intercalate, option, replace, try)
+import Protolude            hiding (intercalate, option, replace, toS,
+                             try)
+import Protolude.Conv       (toS)

 pRequestSelect :: Text -> Either ApiRequestError [Tree SelectItem]
 pRequestSelect selStr =
  mapError $ parse pFieldForest ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)

+pRequestOnConflict :: Text -> Either ApiRequestError  [FieldName]
+pRequestOnConflict oncStr =
+  mapError $ parse pColumns ("failed to parse on_conflict parameter (" <> toS oncStr <> ")") (toS oncStr)
+
 pRequestFilter :: (Text, Text) -> Either ApiRequestError (EmbedPath, Filter)
 pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
  where
@@ -130,12 +134,12 @@ pRelationSelect :: Parser SelectItem
 pRelationSelect = lexeme $ try ( do
    alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
    fld <- pField
-    relationDetail <- optionMaybe (
-        try ( char '+' *> pFieldName ) <|>
-        try ( char '.' *> pFieldName ) -- TODO deprecated, remove in next major version
+    hint <- optionMaybe (
+        try ( char '!' *> pFieldName) <|>
+        -- deprecated, remove in next major version
+        try ( char '.' *> pFieldName)
      )
-
-    return (fld, Nothing, alias, relationDetail)
+    return (fld, Nothing, alias, hint)
  )

 pFieldSelect :: Parser SelectItem
@@ -0,0 +1,25 @@
+{-|
+Module      : PostgREST.Common
+Description : Common helper functions.
+-}
+module PostgREST.Private.Common where
+
+import           Data.Maybe
+import qualified Hasql.Decoders as HD
+import qualified Hasql.Encoders as HE
+import           Protolude
+
+column :: HD.Value a -> HD.Row a
+column = HD.column . HD.nonNullable
+
+nullableColumn :: HD.Value a -> HD.Row (Maybe a)
+nullableColumn = HD.column . HD.nullable
+
+element :: HD.Value a -> HD.Array a
+element = HD.element . HD.nonNullable
+
+param :: HE.Value a -> HE.Params a
+param = HE.param . HE.nonNullable
+
+arrayParam :: HE.Value a -> HE.Params [a]
+arrayParam = param . HE.array . HE.dimension foldl' . HE.element . HE.nonNullable
@@ -0,0 +1,206 @@
+{-# LANGUAGE LambdaCase #-}
+{-|
+Module      : PostgREST.Private.QueryFragment
+Description : Helper functions for PostgREST.QueryBuilder.
+
+Any function that outputs a SqlFragment should be in this module.
+-}
+module PostgREST.Private.QueryFragment where
+
+import qualified Data.HashMap.Strict           as HM
+import           Data.Maybe
+import           Data.Text                     (intercalate,
+                                                isInfixOf, replace,
+                                                toLower)
+import qualified Data.Text                     as T (map, null,
+                                                     takeWhile)
+import           PostgREST.Types
+import           Protolude                     hiding (cast,
+                                                intercalate, replace,
+                                                toLower)
+import           Text.InterpolatedString.Perl6 (qc)
+
+noLocationF :: SqlFragment
+noLocationF = "array[]::text[]"
+
+-- Due to the use of the `unknown` encoder we need to cast '$1' when the value is not used in the main query
+-- otherwise the query will err with a `could not determine data type of parameter $1`.
+-- This happens because `unknown` relies on the context to determine the value type.
+-- The error also happens on raw libpq used with C.
+ignoredBody :: SqlFragment
+ignoredBody = "pgrst_ignored_body AS (SELECT $1::text) "
+
+-- |
+-- These CTEs convert a json object into a json array, this way we can use json_populate_recordset for all json payloads
+-- Otherwise we'd have to use json_populate_record for json objects and json_populate_recordset for json arrays
+-- We do this in SQL to avoid processing the JSON in application code
+normalizedBody :: SqlFragment
+normalizedBody =
+  unwords [
+    "pgrst_payload AS (SELECT $1::json AS json_data),",
+    "pgrst_body AS (",
+      "SELECT",
+        "CASE WHEN json_typeof(json_data) = 'array'",
+          "THEN json_data",
+          "ELSE json_build_array(json_data)",
+        "END AS val",
+      "FROM pgrst_payload)"]
+
+selectBody :: SqlFragment
+selectBody = "(SELECT val FROM pgrst_body)"
+
+pgFmtLit :: SqlFragment -> SqlFragment
+pgFmtLit x =
+ let trimmed = trimNullChars x
+     escaped = "'" <> replace "'" "''" trimmed <> "'"
+     slashed = replace "\\" "\\\\" escaped in
+ if "\\" `isInfixOf` escaped
+   then "E" <> slashed
+   else slashed
+
+pgFmtIdent :: SqlFragment -> SqlFragment
+pgFmtIdent x = "\"" <> replace "\"" "\"\"" (trimNullChars $ toS x) <> "\""
+
+asCsvF :: SqlFragment
+asCsvF = asCsvHeaderF <> " || '\n' || " <> asCsvBodyF
+  where
+    asCsvHeaderF =
+      "(SELECT coalesce(string_agg(a.k, ','), '')" <>
+      "  FROM (" <>
+      "    SELECT json_object_keys(r)::TEXT as k" <>
+      "    FROM ( " <>
+      "      SELECT row_to_json(hh) as r from " <> sourceCTEName <> " as hh limit 1" <>
+      "    ) s" <>
+      "  ) a" <>
+      ")"
+    asCsvBodyF = "coalesce(string_agg(substring(_postgrest_t::text, 2, length(_postgrest_t::text) - 2), '\n'), '')"
+
+asJsonF :: SqlFragment
+asJsonF = "coalesce(json_agg(_postgrest_t), '[]')::character varying"
+
+asJsonSingleF :: SqlFragment --TODO! unsafe when the query actually returns multiple rows, used only on inserting and returning single element
+asJsonSingleF = "coalesce(string_agg(row_to_json(_postgrest_t)::text, ','), '')::character varying "
+
+asBinaryF :: FieldName -> SqlFragment
+asBinaryF fieldName = "coalesce(string_agg(_postgrest_t." <> pgFmtIdent fieldName <> ", ''), '')"
+
+locationF :: [Text] -> SqlFragment
+locationF pKeys = [qc|(
+  WITH data AS (SELECT row_to_json(_) AS row FROM {sourceCTEName} AS _ LIMIT 1)
+  SELECT array_agg(json_data.key || '=' || coalesce('eq.' || json_data.value, 'is.null'))
+  FROM data CROSS JOIN json_each_text(data.row) AS json_data
+  {("WHERE json_data.key IN ('" <> intercalate "','" pKeys <> "')") `emptyOnFalse` null pKeys}
+)|]
+
+fromQi :: QualifiedIdentifier -> SqlFragment
+fromQi t = (if s == "" then "" else pgFmtIdent s <> ".") <> pgFmtIdent n
+  where
+    n = qiName t
+    s = qiSchema t
+
+emptyOnFalse :: Text -> Bool -> Text
+emptyOnFalse val cond = if cond then "" else val
+
+pgFmtColumn :: QualifiedIdentifier -> Text -> SqlFragment
+pgFmtColumn table "*" = fromQi table <> ".*"
+pgFmtColumn table c   = fromQi table <> "." <> pgFmtIdent c
+
+pgFmtField :: QualifiedIdentifier -> Field -> SqlFragment
+pgFmtField table (c, jp) = pgFmtColumn table c <> pgFmtJsonPath jp
+
+pgFmtSelectItem :: QualifiedIdentifier -> SelectItem -> SqlFragment
+pgFmtSelectItem table (f@(fName, jp), Nothing, alias, _) = pgFmtField table f <> pgFmtAs fName jp alias
+pgFmtSelectItem table (f@(fName, jp), Just cast, alias, _) = "CAST (" <> pgFmtField table f <> " AS " <> cast <> " )" <> pgFmtAs fName jp alias
+
+pgFmtOrderTerm :: QualifiedIdentifier -> OrderTerm -> SqlFragment
+pgFmtOrderTerm qi ot = unwords [
+  toS . pgFmtField qi $ otTerm ot,
+  maybe "" show $ otDirection ot,
+  maybe "" show $ otNullOrder ot]
+
+pgFmtFilter :: QualifiedIdentifier -> Filter -> SqlFragment
+pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper of
+   Op op val  -> pgFmtFieldOp op <> " " <> case op of
+     "like"  -> unknownLiteral (T.map star val)
+     "ilike" -> unknownLiteral (T.map star val)
+     "is"    -> whiteList val
+     _       -> unknownLiteral val
+
+   In vals -> pgFmtField table fld <> " " <>
+    let emptyValForIn = "= any('{}') " in -- Workaround because for postgresql "col IN ()" is invalid syntax, we instead do "col = any('{}')"
+    case (&&) (length vals == 1) . T.null <$> headMay vals of
+      Just False -> sqlOperator "in" <> "(" <> intercalate ", " (map unknownLiteral vals) <> ") "
+      Just True  -> emptyValForIn
+      Nothing    -> emptyValForIn
+
+   Fts op lang val ->
+     pgFmtFieldOp op
+       <> "("
+       <> maybe "" ((<> ", ") . pgFmtLit) lang
+       <> unknownLiteral val
+       <> ") "
+ where
+   pgFmtFieldOp op = pgFmtField table fld <> " " <> sqlOperator op
+   sqlOperator o = HM.lookupDefault "=" o operators
+   notOp = if hasNot then "NOT" else ""
+   star c = if c == '*' then '%' else c
+   unknownLiteral = (<> "::unknown ") . pgFmtLit
+   whiteList :: Text -> SqlFragment
+   whiteList v = fromMaybe
+     (toS (pgFmtLit v) <> "::unknown ")
+     (find ((==) . toLower $ v) ["null","true","false"])
+
+pgFmtJoinCondition :: JoinCondition -> SqlFragment
+pgFmtJoinCondition (JoinCondition (qi1, col1) (qi2, col2)) =
+  pgFmtColumn qi1 col1 <> " = " <> pgFmtColumn qi2 col2
+
+pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> SqlFragment
+pgFmtLogicTree qi (Expr hasNot op forest) = notOp <> " (" <> intercalate (" " <> show op <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
+  where notOp =  if hasNot then "NOT" else ""
+pgFmtLogicTree qi (Stmnt flt) = pgFmtFilter qi flt
+
+pgFmtJsonPath :: JsonPath -> SqlFragment
+pgFmtJsonPath = \case
+  []             -> ""
+  (JArrow x:xs)  -> "->" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
+  (J2Arrow x:xs) -> "->>" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
+  where
+    pgFmtJsonOperand (JKey k) = pgFmtLit k
+    pgFmtJsonOperand (JIdx i) = pgFmtLit i <> "::int"
+
+pgFmtAs :: FieldName -> JsonPath -> Maybe Alias -> SqlFragment
+pgFmtAs _ [] Nothing = ""
+pgFmtAs fName jp Nothing = case jOp <$> lastMay jp of
+  Just (JKey key) -> " AS " <> pgFmtIdent key
+  Just (JIdx _)   -> " AS " <> pgFmtIdent (fromMaybe fName lastKey)
+    -- We get the lastKey because on:
+    -- `select=data->1->mycol->>2`, we need to show the result as [ {"mycol": ..}, {"mycol": ..} ]
+    -- `select=data->3`, we need to show the result as [ {"data": ..}, {"data": ..} ]
+    where lastKey = jVal <$> find (\case JKey{} -> True; _ -> False) (jOp <$> reverse jp)
+  Nothing -> ""
+pgFmtAs _ _ (Just alias) = " AS " <> pgFmtIdent alias
+
+trimNullChars :: Text -> Text
+trimNullChars = T.takeWhile (/= '\x0')
+
+countF :: SqlQuery -> Bool -> (SqlFragment, SqlFragment)
+countF countQuery shouldCount =
+  if shouldCount
+    then (
+        ", pgrst_source_count AS (" <> countQuery <> ")"
+      , "(SELECT pg_catalog.count(*) FROM pgrst_source_count)" )
+    else (
+        mempty
+      , "null::bigint")
+
+returningF :: QualifiedIdentifier -> [FieldName] -> SqlFragment
+returningF qi returnings =
+  if null returnings
+    then "RETURNING 1" -- For mutation cases where there's no ?select, we return 1 to know how many rows were modified
+    else "RETURNING " <> intercalate ", " (pgFmtColumn qi <$> returnings)
+
+responseHeadersF :: PgVersion -> SqlFragment
+responseHeadersF pgVer =
+  if pgVer >= pgVersion96
+    then "coalesce(nullif(current_setting('response.headers', true), ''), '[]')" :: Text -- nullif is used because of https://gist.github.com/steve-chavez/8d7033ea5655096903f3b52f8ed09a15
+    else "'[]'" :: Text
@@ -1,255 +1,41 @@
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
-{-# LANGUAGE LambdaCase            #-}
 {-# OPTIONS_GHC -fno-warn-orphans  #-}
 {-|
 Module      : PostgREST.QueryBuilder
-Description : PostgREST SQL generating functions.
+Description : PostgREST SQL queries generating functions.

 This module provides functions to consume data types that
-represent database objects (e.g. Relation, Schema, SqlQuery)
-and produces SQL Statements.
-
-Any function that outputs a SQL fragment should be in this module.
+represent database queries (e.g. ReadRequest, MutateRequest) and SqlFragment
+to produce SqlQuery type outputs.
 -}
 module PostgREST.QueryBuilder (
-    callProc
-  , createReadStatement
-  , createWriteStatement
-  , pgFmtIdent
-  , pgFmtLit
-  , requestToQuery
-  , requestToCountQuery
-  , unquoted
-  , ResultsWithCount
-  , pgFmtSetLocal
-  , pgFmtSetLocalSearchPath
+    readRequestToQuery
+  , mutateRequestToQuery
+  , readRequestToCountQuery
+  , requestToCallProcQuery
+  , limitedQuery
+  , setLocalQuery
+  , setLocalSearchPathQuery
  ) where

-import qualified Data.Aeson            as JSON
-import qualified Data.ByteString.Char8 as BS
-import qualified Data.HashMap.Strict   as HM
-import qualified Data.Set              as S
-import qualified Data.Text             as T (map, null, takeWhile)
-import qualified Data.Text.Encoding    as T
-import qualified Hasql.Decoders        as HD
-import qualified Hasql.Encoders        as HE
-import qualified Hasql.Statement       as H
+import qualified Data.Set as S

-import Data.Scientific               (FPFormat (..), formatScientific,
-                                      isInteger)
-import Data.Text                     (intercalate, isInfixOf, replace,
-                                      toLower, unwords)
-import Data.Tree                     (Tree (..))
-import Text.InterpolatedString.Perl6 (qc)
+import Data.Text (intercalate)
+import Data.Tree (Tree (..))

 import Data.Maybe

-import PostgREST.ApiRequest (PreferRepresentation (..))
-import PostgREST.RangeQuery (allRange, rangeLimit, rangeOffset)
+import PostgREST.Private.QueryFragment
+import PostgREST.RangeQuery            (allRange, rangeLimit,
+                                        rangeOffset)
 import PostgREST.Types
-import Protolude            hiding (cast, intercalate, replace)
+import Protolude                       hiding (cast, intercalate,
+                                        replace)

-column :: HD.Value a -> HD.Row a
-column = HD.column . HD.nonNullable
-
-nullableColumn :: HD.Value a -> HD.Row (Maybe a)
-nullableColumn = HD.column . HD.nullable
-
-element :: HD.Value a -> HD.Array a
-element = HD.element . HD.nonNullable
-
-param :: HE.Value a -> HE.Params a
-param = HE.param . HE.nonNullable
-
-{-| The generic query result format used by API responses. The location header
-    is represented as a list of strings containing variable bindings like
-    @"k1=eq.42"@, or the empty list if there is no location header.
-}
-type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString)
-
-standardRow :: HD.Row ResultsWithCount
-standardRow = (,,,) <$> nullableColumn HD.int8 <*> column HD.int8
-                    <*> column header <*> column HD.bytea
-  where
-    header = HD.array $ HD.dimension replicateM $ element HD.bytea
-
-noLocationF :: Text
-noLocationF = "array[]::text[]"
-
-{-| Read and Write api requests use a similar response format which includes
-    various record counts and possible location header. This is the decoder
-    for that common type of query.
-}
-decodeStandard :: HD.Result ResultsWithCount
-decodeStandard =
-  HD.singleRow standardRow
-
-decodeStandardMay :: HD.Result (Maybe ResultsWithCount)
-decodeStandardMay =
-  HD.rowMaybe standardRow
-
-createReadStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool -> Maybe FieldName ->
-                       H.Statement () ResultsWithCount
-createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField =
-  unicodeStatement sql HE.noParams decodeStandard False
- where
-  sql = [qc|
-      WITH {sourceCTEName} AS ({selectQuery}) SELECT {cols}
-      FROM ( SELECT * FROM {sourceCTEName}) _postgrest_t |]
-  countResultF = if countTotal then "("<>countQuery<>")" else "null"
-  cols = intercalate ", " [
-      countResultF <> " AS total_result_set",
-      "pg_catalog.count(_postgrest_t) AS page_total",
-      noLocationF <> " AS header",
-      bodyF <> " AS body"
-    ]
-  bodyF
-    | asCsv = asCsvF
-    | isSingle = asJsonSingleF
-    | isJust binaryField = asBinaryF $ fromJust binaryField
-    | otherwise = asJsonF
-
-
-createWriteStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool ->
-                        PreferRepresentation -> [Text] ->
-                        H.Statement ByteString (Maybe ResultsWithCount)
-createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys =
-  unicodeStatement sql (param HE.unknown) decodeStandardMay True
-
- where
-  sql = case rep of
-    None -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT '', 0, {noLocationF}, '' |]
-    HeadersOnly -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT {cols}
-      FROM (SELECT 1 FROM {sourceCTEName}) _postgrest_t |]
-    Full -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT {cols}
-      FROM ({selectQuery}) _postgrest_t |]
-
-  cols = intercalate ", " [
-      "'' AS total_result_set", -- when updateing it does not make sense
-      "pg_catalog.count(_postgrest_t) AS page_total",
-      if isInsert
-        then unwords [
-          "CASE",
-            "WHEN pg_catalog.count(_postgrest_t) = 1 THEN",
-              "coalesce(" <> locationF pKeys <> ", " <> noLocationF <> ")",
-            "ELSE " <> noLocationF,
-          "END AS header"]
-        else noLocationF <> "AS header",
-      if rep == Full
-         then bodyF <> " AS body"
-         else "''"
-    ]
-
-  bodyF
-    | asCsv = asCsvF
-    | wantSingle = asJsonSingleF
-    | otherwise = asJsonF
-
-type ProcResults = (Maybe Int64, Int64, ByteString, ByteString)
-callProc :: QualifiedIdentifier -> [PgArg] -> Bool -> SqlQuery -> SqlQuery -> Bool ->
-            Bool -> Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion ->
-            H.Statement ByteString (Maybe ProcResults)
-callProc qi pgArgs returnsScalar selectQuery countQuery countTotal isSingle paramsAsSingleObject asCsv asBinary binaryField pgVer =
-  unicodeStatement sql (param HE.unknown) decodeProc True
-  where
-    sql =[qc|
-      WITH
-      {argsRecord},
-      {sourceCTEName} AS (
-        {sourceBody}
-      )
-      SELECT
-        {countResultF} AS total_result_set,
-        pg_catalog.count(_postgrest_t) AS page_total,
-        {bodyF} AS body,
-        {responseHeaders} AS response_headers
-      FROM ({selectQuery}) _postgrest_t;|]
-
-    (argsRecord, args)
-      | paramsAsSingleObject = ("_args_record AS (SELECT NULL)", "$1::json")
-      | null pgArgs = (ignoredBody, "")
-      | otherwise = (
-          unwords [
-            normalizedBody <> ",",
-            "_args_record AS (",
-              "SELECT * FROM json_to_recordset(" <> selectBody <> ") AS _(" <>
-                intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> " " <> pgaType a) <$> pgArgs) <> ")",
-            ")"]
-         , intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> " := _args_record." <> pgFmtIdent (pgaName a)) <$> pgArgs))
-
-    sourceBody :: SqlFragment
-    sourceBody
-      | paramsAsSingleObject || null pgArgs =
-          if returnsScalar
-            then [qc| SELECT {fromQi qi}({args}) |]
-            else [qc| SELECT * FROM {fromQi qi}({args}) |]
-      | otherwise =
-          if returnsScalar
-            then [qc| SELECT {fromQi qi}({args}) FROM _args_record |]
-            else [qc| SELECT _.*
-                      FROM _args_record,
-                      LATERAL ( SELECT * FROM {fromQi qi}({args}) ) _ |]
-
-    bodyF
-     | returnsScalar = scalarBodyF
-     | isSingle = asJsonSingleF
-     | asCsv = asCsvF
-     | isJust binaryField = asBinaryF $ fromJust binaryField
-     | otherwise = asJsonF
-
-    scalarBodyF
-     | asBinary = asBinaryF _procName
-     | otherwise = unwords [
-        "CASE",
-          "WHEN pg_catalog.count(_postgrest_t) = 1",
-            "THEN (json_agg(_postgrest_t." <> pgFmtIdent _procName <> ")->0)::character varying",
-            "ELSE (json_agg(_postgrest_t." <> pgFmtIdent _procName <> "))::character varying",
-        "END"]
-
-    countResultF = if countTotal then "( "<> countQuery <> ")" else "null::bigint" :: Text
-    _procName = qiName qi
-    responseHeaders =
-      if pgVer >= pgVersion96
-        then "coalesce(nullif(current_setting('response.headers', true), ''), '[]')" :: Text -- nullif is used because of https://gist.github.com/steve-chavez/8d7033ea5655096903f3b52f8ed09a15
-        else "'[]'" :: Text
-
-    decodeProc = HD.rowMaybe procRow
-    procRow = (,,,) <$> nullableColumn HD.int8 <*> column HD.int8
-                    <*> column HD.bytea <*> column HD.bytea
-
-pgFmtIdent :: SqlFragment -> SqlFragment
-pgFmtIdent x = "\"" <> replace "\"" "\"\"" (trimNullChars $ toS x) <> "\""
-
-pgFmtLit :: SqlFragment -> SqlFragment
-pgFmtLit x =
- let trimmed = trimNullChars x
-     escaped = "'" <> replace "'" "''" trimmed <> "'"
-     slashed = replace "\\" "\\\\" escaped in
- if "\\" `isInfixOf` escaped
-   then "E" <> slashed
-   else slashed
-
-requestToCountQuery :: Schema -> DbRequest -> SqlQuery
-requestToCountQuery _ (DbMutate _) = witness
-requestToCountQuery schema (DbRead (Node (Select{where_=logicForest}, (mainTbl, _, _, _, _)) _)) =
- unwords [
-   "SELECT pg_catalog.count(*)",
-   "FROM ", fromQi qi,
-    ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest
-   ]
- where
-   qi = removeSourceCTESchema schema mainTbl
-
-requestToQuery :: Schema -> Bool -> DbRequest -> SqlQuery
-requestToQuery schema isParent (DbRead (Node (Select colSelects tbl tblAlias implJoins logicForest joinConditions_ ordts range, _) forest)) =
+readRequestToQuery :: ReadRequest -> SqlQuery
+readRequestToQuery (Node (Select colSelects mainQi tblAlias implJoins logicForest joinConditions_ ordts range, _) forest) =
  unwords [
    "SELECT " <> intercalate ", " (map (pgFmtSelectItem qi) colSelects ++ selects),
    "FROM " <> intercalate ", " (tabl : implJs),
@@ -257,51 +43,42 @@ requestToQuery schema isParent (DbRead (Node (Select colSelects tbl tblAlias imp
    ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest ++ map pgFmtJoinCondition joinConditions_))
      `emptyOnFalse` (null logicForest && null joinConditions_),
    ("ORDER BY " <> intercalate ", " (map (pgFmtOrderTerm qi) ordts)) `emptyOnFalse` null ordts,
-    ("LIMIT " <> maybe "ALL" show (rangeLimit range) <> " OFFSET " <> show (rangeOffset range)) `emptyOnFalse` (isParent || range == allRange) ]
-
+    ("LIMIT " <> maybe "ALL" show (rangeLimit range) <> " OFFSET " <> show (rangeOffset range)) `emptyOnFalse` (range == allRange)
+    ]
  where
-    implJs = fromQi . QualifiedIdentifier schema <$> implJoins
-    mainQi = removeSourceCTESchema schema tbl
+    implJs = fromQi <$> implJoins
    tabl = fromQi mainQi <> maybe mempty (\a -> " AS " <> pgFmtIdent a) tblAlias
    qi = maybe mainQi (QualifiedIdentifier mempty) tblAlias
+    (joins, selects) = foldr getJoinsSelects ([],[]) forest

-    (joins, selects) = foldr getQueryParts ([],[]) forest
+getJoinsSelects :: ReadRequest -> ([SqlFragment], [SqlFragment]) -> ([SqlFragment], [SqlFragment])
+getJoinsSelects rr@(Node (_, (name, Just Relation{relType=relTyp,relTable=Table{tableName=table}}, alias, _, _)) _) (j,s) =
+  let subquery = readRequestToQuery rr in
+  case relTyp of
+    M2O ->
+      let aliasOrName = fromMaybe name alias
+          localTableName = pgFmtIdent $ table <> "_" <> aliasOrName
+          sel = "row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName
+          joi = " LEFT JOIN LATERAL( " <> subquery <> " ) AS " <> localTableName <> " ON TRUE " in
+      (joi:j,sel:s)
+    _ ->
+      let sel = "COALESCE (("
+             <> "SELECT json_agg(" <> pgFmtIdent table <> ".*) "
+             <> "FROM (" <> subquery <> ") " <> pgFmtIdent table
+             <> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias) in
+      (j,sel:s)
+getJoinsSelects (Node (_, (_, Nothing, _, _, _)) _) _ = ([], [])

-    getQueryParts :: Tree ReadNode -> ([SqlFragment], [SqlFragment]) -> ([SqlFragment], [SqlFragment])
-    getQueryParts (Node n@(_, (name, Just Relation{relType=Child,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (j,sel:s)
-      where
-        sel = "COALESCE(("
-           <> "SELECT json_agg(" <> pgFmtIdent table <> ".*) "
-           <> "FROM (" <> subquery <> ") " <> pgFmtIdent table
-           <> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
-           where subquery = requestToQuery schema False (DbRead (Node n forst))
-    getQueryParts (Node n@(_, (name, Just Relation{relType=Parent,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (joi:j,sel:s)
-      where
-        aliasOrName = fromMaybe name alias
-        localTableName = pgFmtIdent $ table <> "_" <> aliasOrName
-        sel = "row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName
-        joi = " LEFT JOIN LATERAL( " <> subquery <> " ) AS " <> localTableName <> " ON TRUE "
-          where subquery = requestToQuery schema True (DbRead (Node n forst))
-    getQueryParts (Node n@(_, (name, Just Relation{relType=Many,relTable=Table{tableName=table}}, alias, _, _)) forst) (j,s) = (j,sel:s)
-      where
-        sel = "COALESCE (("
-           <> "SELECT json_agg(" <> pgFmtIdent table <> ".*) "
-           <> "FROM (" <> subquery <> ") " <> pgFmtIdent table
-           <> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
-           where subquery = requestToQuery schema False (DbRead (Node n forst))
-    --the following is just to remove the warning
-    --getQueryParts is not total but requestToQuery is called only after addJoinConditions which ensures the only
-    --posible relations are Child Parent Many
-    getQueryParts _ _ = witness
-requestToQuery schema _ (DbMutate (Insert mainTbl iCols onConflct putConditions returnings)) =
+mutateRequestToQuery :: MutateRequest -> SqlQuery
+mutateRequestToQuery (Insert mainQi iCols onConflct putConditions returnings) =
  unwords [
    "WITH " <> normalizedBody,
-    "INSERT INTO ", fromQi qi, if S.null iCols then " " else "(" <> cols <> ")",
+    "INSERT INTO ", fromQi mainQi, if S.null iCols then " " else "(" <> cols <> ")",
    unwords [
      "SELECT " <> cols <> " FROM",
-      "json_populate_recordset", "(null::", fromQi qi, ", " <> selectBody <> ") _",
+      "json_populate_recordset", "(null::", fromQi mainQi, ", " <> selectBody <> ") _",
      -- Only used for PUT
-      ("WHERE " <> intercalate " AND " (pgFmtLogicTree (QualifiedIdentifier "" "_") <$> putConditions)) `emptyOnFalse` null putConditions],
+      ("WHERE " <> intercalate " AND " (pgFmtLogicTree (QualifiedIdentifier mempty "_") <$> putConditions)) `emptyOnFalse` null putConditions],
    maybe "" (\(oncDo, oncCols) -> (
      "ON CONFLICT(" <> intercalate ", " (pgFmtIdent <$> oncCols) <> ") " <> case oncDo of
      IgnoreDuplicates ->
@@ -311,201 +88,106 @@ requestToQuery schema _ (DbMutate (Insert mainTbl iCols onConflct putConditions
           then "DO NOTHING"
           else "DO UPDATE SET " <> intercalate ", " (pgFmtIdent <> const " = EXCLUDED." <> pgFmtIdent <$> S.toList iCols)
                                   ) `emptyOnFalse` null oncCols) onConflct,
-    ("RETURNING " <> intercalate ", " (map (pgFmtColumn qi) returnings)) `emptyOnFalse` null returnings]
+    returningF mainQi returnings
+    ]
  where
-    qi = QualifiedIdentifier schema mainTbl
    cols = intercalate ", " $ pgFmtIdent <$> S.toList iCols
-requestToQuery schema _ (DbMutate (Update mainTbl uCols logicForest returnings)) =
+mutateRequestToQuery (Update mainQi uCols logicForest returnings) =
  if S.null uCols
-    then "WITH " <> ignoredBody <> "SELECT null WHERE false" -- if there are no columns we cannot do UPDATE table SET {empty}, it'd be invalid syntax
+    -- if there are no columns we cannot do UPDATE table SET {empty}, it'd be invalid syntax
+    -- selecting an empty resultset from mainQi gives us the column names to prevent errors when using &select=
+    -- the select has to be based on "returnings" to make computed overloaded functions not throw
+    then "WITH " <> ignoredBody <> "SELECT " <> empty_body_returned_columns <> " FROM " <> fromQi mainQi <> " WHERE false"
    else
      unwords [
        "WITH " <> normalizedBody,
-        "UPDATE " <> fromQi qi <> " SET " <> cols,
-        "FROM (SELECT * FROM json_populate_recordset", "(null::", fromQi qi, ", " <> selectBody <> ")) _ ",
-        ("WHERE " <> intercalate " AND " (pgFmtLogicTree qi <$> logicForest)) `emptyOnFalse` null logicForest,
-        ("RETURNING " <> intercalate ", " (pgFmtColumn qi <$> returnings)) `emptyOnFalse` null returnings
+        "UPDATE " <> fromQi mainQi <> " SET " <> cols,
+        "FROM (SELECT * FROM json_populate_recordset", "(null::", fromQi mainQi, ", " <> selectBody <> ")) _ ",
+        ("WHERE " <> intercalate " AND " (pgFmtLogicTree mainQi <$> logicForest)) `emptyOnFalse` null logicForest,
+        returningF mainQi returnings
        ]
  where
-    qi = QualifiedIdentifier schema mainTbl
    cols = intercalate ", " (pgFmtIdent <> const " = _." <> pgFmtIdent <$> S.toList uCols)
-requestToQuery schema _ (DbMutate (Delete mainTbl logicForest returnings)) =
+    empty_body_returned_columns :: SqlFragment
+    empty_body_returned_columns
+      | null returnings = "NULL"
+      | otherwise       = intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName mainQi) <$> returnings)
+mutateRequestToQuery (Delete mainQi logicForest returnings) =
  unwords [
    "WITH " <> ignoredBody,
-    "DELETE FROM ", fromQi qi,
-    ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest,
-    ("RETURNING " <> intercalate ", " (map (pgFmtColumn qi) returnings)) `emptyOnFalse` null returnings
+    "DELETE FROM ", fromQi mainQi,
+    ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree mainQi) logicForest)) `emptyOnFalse` null logicForest,
+    returningF mainQi returnings
    ]
-  where
-    qi = QualifiedIdentifier schema mainTbl

-- Due to the use of the `unknown` encoder we need to cast '$1' when the value is not used in the main query
-- otherwise the query will err with a `could not determine data type of parameter $1`.
-- This happens because `unknown` relies on the context to determine the value type.
-- The error also happens on raw libpq used with C.
-ignoredBody :: SqlFragment
-ignoredBody = "ignored_body AS (SELECT $1::text) "
-
-- |
-- These CTEs convert a json object into a json array, this way we can use json_populate_recordset for all json payloads
-- Otherwise we'd have to use json_populate_record for json objects and json_populate_recordset for json arrays
-- We do this in SQL to avoid processing the JSON in application code
-normalizedBody :: SqlFragment
-normalizedBody =
+requestToCallProcQuery :: QualifiedIdentifier -> [PgArg] -> Bool -> Maybe PreferParameters -> [FieldName] -> SqlQuery
+requestToCallProcQuery qi pgArgs returnsScalar preferParams returnings =
  unwords [
-    "pgrst_payload AS (SELECT $1::json AS json_data),",
-    "pgrst_body AS (",
-      "SELECT",
-        "CASE WHEN json_typeof(json_data) = 'array'",
-          "THEN json_data",
-          "ELSE json_build_array(json_data)",
-        "END AS val",
-      "FROM pgrst_payload)"]
-
-selectBody :: SqlFragment
-selectBody = "(SELECT val FROM pgrst_body)"
-
-removeSourceCTESchema :: Schema -> TableName -> QualifiedIdentifier
-removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == sourceCTEName then "" else schema) tbl
-
-unquoted :: JSON.Value -> Text
-unquoted (JSON.String t) = t
-unquoted (JSON.Number n) =
-  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
-unquoted (JSON.Bool b) = show b
-unquoted v = toS $ JSON.encode v
-
-- private functions
-asCsvF :: SqlFragment
-asCsvF = asCsvHeaderF <> " || '\n' || " <> asCsvBodyF
+    "WITH",
+    argsCTE,
+    sourceBody ]
  where
-    asCsvHeaderF =
-      "(SELECT coalesce(string_agg(a.k, ','), '')" <>
-      "  FROM (" <>
-      "    SELECT json_object_keys(r)::TEXT as k" <>
-      "    FROM ( " <>
-      "      SELECT row_to_json(hh) as r from " <> sourceCTEName <> " as hh limit 1" <>
-      "    ) s" <>
-      "  ) a" <>
-      ")"
-    asCsvBodyF = "coalesce(string_agg(substring(_postgrest_t::text, 2, length(_postgrest_t::text) - 2), '\n'), '')"
+    paramsAsSingleObject    = preferParams == Just SingleObject
+    paramsAsMultipleObjects = preferParams == Just MultipleObjects

-asJsonF :: SqlFragment
-asJsonF = "coalesce(json_agg(_postgrest_t), '[]')::character varying"
+    (argsCTE, args)
+      | null pgArgs = (ignoredBody, "")
+      | paramsAsSingleObject = ("pgrst_args AS (SELECT NULL)", "$1::json")
+      | otherwise = (
+          unwords [
+            normalizedBody <> ",",
+            "pgrst_args AS (",
+              "SELECT * FROM json_to_recordset(" <> selectBody <> ") AS _(" <> fmtArgs (\a -> " " <> pgaType a) <> ")",
+            ")"]
+         , if paramsAsMultipleObjects
+             then fmtArgs (\a -> " := pgrst_args." <> pgFmtIdent (pgaName a))
+             else fmtArgs (\a -> " := (SELECT " <> pgFmtIdent (pgaName a) <> " FROM pgrst_args LIMIT 1)")
+        )

-asJsonSingleF :: SqlFragment --TODO! unsafe when the query actually returns multiple rows, used only on inserting and returning single element
-asJsonSingleF = "coalesce(string_agg(row_to_json(_postgrest_t)::text, ','), '')::character varying "
+    fmtArgs :: (PgArg -> SqlFragment) -> SqlFragment
+    fmtArgs argFrag = intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> argFrag a) <$> pgArgs)

-asBinaryF :: FieldName -> SqlFragment
-asBinaryF fieldName = "coalesce(string_agg(_postgrest_t." <> pgFmtIdent fieldName <> ", ''), '')"
+    sourceBody :: SqlFragment
+    sourceBody
+      | paramsAsMultipleObjects =
+          if returnsScalar
+            then "SELECT " <> callIt <> " AS pgrst_scalar FROM pgrst_args"
+            else unwords [ "SELECT pgrst_lat_args.*"
+                         , "FROM pgrst_args,"
+                         , "LATERAL ( SELECT " <> returned_columns <> " FROM " <> callIt <> " ) pgrst_lat_args" ]
+      | otherwise =
+          if returnsScalar
+            then "SELECT " <> callIt <> " AS pgrst_scalar"
+            else "SELECT " <> returned_columns <> " FROM " <> callIt

-locationF :: [Text] -> SqlFragment
-locationF pKeys = [qc|(
-  WITH data AS (SELECT row_to_json(_) AS row FROM {sourceCTEName} AS _ LIMIT 1)
-  SELECT array_agg(json_data.key || '=' || coalesce('eq.' || json_data.value, 'is.null'))
-  FROM data CROSS JOIN json_each_text(data.row) AS json_data
-  {("WHERE json_data.key IN ('" <> intercalate "','" pKeys <> "')") `emptyOnFalse` null pKeys}
-)|]
+    callIt :: SqlFragment
+    callIt = fromQi qi <> "(" <> args <> ")"

-fromQi :: QualifiedIdentifier -> SqlFragment
-fromQi t = (if s == "" then "" else pgFmtIdent s <> ".") <> pgFmtIdent n
-  where
-    n = qiName t
-    s = qiSchema t
+    returned_columns :: SqlFragment
+    returned_columns
+      | null returnings = "*"
+      | otherwise       = intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName qi) <$> returnings)

-unicodeStatement :: Text -> HE.Params a -> HD.Result b -> Bool -> H.Statement a b
-unicodeStatement = H.Statement . T.encodeUtf8

-emptyOnFalse :: Text -> Bool -> Text
-emptyOnFalse val cond = if cond then "" else val
+-- | SQL query meant for COUNTing the root node of the Tree.
+-- It only takes WHERE into account and doesn't include LIMIT/OFFSET because it would reduce the COUNT.
+-- SELECT 1 is done instead of SELECT * to prevent doing expensive operations(like functions based on the columns)
+-- inside the FROM target.
+readRequestToCountQuery :: ReadRequest -> SqlQuery
+readRequestToCountQuery (Node (Select{from=qi, where_=logicForest}, _) _) =
+ unwords [
+   "SELECT 1",
+   "FROM " <> fromQi qi,
+   ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest
+   ]

-pgFmtColumn :: QualifiedIdentifier -> Text -> SqlFragment
-pgFmtColumn table "*" = fromQi table <> ".*"
-pgFmtColumn table c   = fromQi table <> "." <> pgFmtIdent c
+limitedQuery :: SqlQuery -> Maybe Integer -> SqlQuery
+limitedQuery query maxRows = query <> maybe mempty (\x -> " LIMIT " <> show x) maxRows

-pgFmtField :: QualifiedIdentifier -> Field -> SqlFragment
-pgFmtField table (c, jp) = pgFmtColumn table c <> pgFmtJsonPath jp
-
-pgFmtSelectItem :: QualifiedIdentifier -> SelectItem -> SqlFragment
-pgFmtSelectItem table (f@(fName, jp), Nothing, alias, _) = pgFmtField table f <> pgFmtAs fName jp alias
-pgFmtSelectItem table (f@(fName, jp), Just cast, alias, _) = "CAST (" <> pgFmtField table f <> " AS " <> cast <> " )" <> pgFmtAs fName jp alias
-
-pgFmtOrderTerm :: QualifiedIdentifier -> OrderTerm -> SqlFragment
-pgFmtOrderTerm qi ot = unwords [
-  toS . pgFmtField qi $ otTerm ot,
-  maybe "" show $ otDirection ot,
-  maybe "" show $ otNullOrder ot]
-
-pgFmtFilter :: QualifiedIdentifier -> Filter -> SqlFragment
-pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper of
-   Op op val  -> pgFmtFieldOp op <> " " <> case op of
-     "like"  -> unknownLiteral (T.map star val)
-     "ilike" -> unknownLiteral (T.map star val)
-     "is"    -> whiteList val
-     _       -> unknownLiteral val
-
-   In vals -> pgFmtField table fld <> " " <>
-    let emptyValForIn = "= any('{}') " in -- Workaround because for postgresql "col IN ()" is invalid syntax, we instead do "col = any('{}')"
-    case (&&) (length vals == 1) . T.null <$> headMay vals of
-      Just False -> sqlOperator "in" <> "(" <> intercalate ", " (map unknownLiteral vals) <> ") "
-      Just True  -> emptyValForIn
-      Nothing    -> emptyValForIn
-
-   Fts op lang val ->
-     pgFmtFieldOp op
-       <> "("
-       <> maybe "" ((<> ", ") . pgFmtLit) lang
-       <> unknownLiteral val
-       <> ") "
- where
-   pgFmtFieldOp op = pgFmtField table fld <> " " <> sqlOperator op
-   sqlOperator o = HM.lookupDefault "=" o operators
-   notOp = if hasNot then "NOT" else ""
-   star c = if c == '*' then '%' else c
-   unknownLiteral = (<> "::unknown ") . pgFmtLit
-   whiteList :: Text -> SqlFragment
-   whiteList v = fromMaybe
-     (toS (pgFmtLit v) <> "::unknown ")
-     (find ((==) . toLower $ v) ["null","true","false"])
-
-pgFmtJoinCondition :: JoinCondition -> SqlFragment
-pgFmtJoinCondition (JoinCondition (qi, col1) (QualifiedIdentifier schema fTable, col2)) =
-  pgFmtColumn qi col1 <> " = " <>
-  pgFmtColumn (removeSourceCTESchema schema fTable) col2
-
-pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> SqlFragment
-pgFmtLogicTree qi (Expr hasNot op forest) = notOp <> " (" <> intercalate (" " <> show op <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
-  where notOp =  if hasNot then "NOT" else ""
-pgFmtLogicTree qi (Stmnt flt) = pgFmtFilter qi flt
-
-pgFmtJsonPath :: JsonPath -> SqlFragment
-pgFmtJsonPath = \case
-  []             -> ""
-  (JArrow x:xs)  -> "->" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
-  (J2Arrow x:xs) -> "->>" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
-  where
-    pgFmtJsonOperand (JKey k) = pgFmtLit k
-    pgFmtJsonOperand (JIdx i) = pgFmtLit i <> "::int"
-
-pgFmtAs :: FieldName -> JsonPath -> Maybe Alias -> SqlFragment
-pgFmtAs _ [] Nothing = ""
-pgFmtAs fName jp Nothing = case jOp <$> lastMay jp of
-  Just (JKey key) -> " AS " <> pgFmtIdent key
-  Just (JIdx _)   -> " AS " <> pgFmtIdent (fromMaybe fName lastKey)
-    -- We get the lastKey because on:
-    -- `select=data->1->mycol->>2`, we need to show the result as [ {"mycol": ..}, {"mycol": ..} ]
-    -- `select=data->3`, we need to show the result as [ {"data": ..}, {"data": ..} ]
-    where lastKey = jVal <$> find (\case JKey{} -> True; _ -> False) (jOp <$> reverse jp)
-  Nothing -> ""
-pgFmtAs _ _ (Just alias) = " AS " <> pgFmtIdent alias
-
-pgFmtSetLocal :: Text -> (Text, Text) -> SqlFragment
-pgFmtSetLocal prefix (k, v) =
+setLocalQuery :: Text -> (Text, Text) -> SqlQuery
+setLocalQuery prefix (k, v) =
  "SET LOCAL " <> pgFmtIdent (prefix <> k) <> " = " <> pgFmtLit v <> ";"

-pgFmtSetLocalSearchPath :: [Text] -> SqlFragment
-pgFmtSetLocalSearchPath vals =
+setLocalSearchPathQuery :: [Text] -> SqlQuery
+setLocalSearchPathQuery vals =
  "SET LOCAL search_path = " <> intercalate ", " (pgFmtLit <$> vals) <> ";"
-
-trimNullChars :: Text -> Text
-trimNullChars = T.takeWhile (/= '\x0')
@@ -1,6 +1,6 @@
 {-|
 Module      : PostgREST.RangeQuery
-Description : Logic regarding the `Range` header and `limit`, `offset` querystring arguments.
+Description : Logic regarding the `Range`/`Content-Range` headers and `limit`/`offset` querystring arguments.
 -}
 module PostgREST.RangeQuery (
  rangeParse
@@ -11,6 +11,8 @@ module PostgREST.RangeQuery (
 , rangeGeq
 , allRange
 , NonnegRange
+, rangeStatusHeader
+, contentRangeH
 ) where

 import qualified Data.ByteString.Char8 as BS
@@ -22,8 +24,10 @@ import Control.Applicative
 import Data.Ranged.Boundaries
 import Data.Ranged.Ranges
 import Network.HTTP.Types.Header
+import Network.HTTP.Types.Status

-import Protolude
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)

 type NonnegRange = Range Integer

@@ -70,3 +74,30 @@ allRange = rangeGeq 0
 rangeLeq :: Integer -> NonnegRange
 rangeLeq n =
  Range BoundaryBelowAll (BoundaryAbove n)
+
+rangeStatusHeader :: NonnegRange -> Int64 -> Maybe Int64 -> (Status, Header)
+rangeStatusHeader topLevelRange queryTotal tableTotal =
+  let lower = rangeOffset topLevelRange
+      upper = lower + toInteger queryTotal - 1
+      contentRange = contentRangeH lower upper (toInteger <$> tableTotal)
+      status = rangeStatus lower upper (toInteger <$> tableTotal)
+  in (status, contentRange)
+  where
+    rangeStatus :: Integer -> Integer -> Maybe Integer -> Status
+    rangeStatus _ _ Nothing = status200
+    rangeStatus lower upper (Just total)
+      | lower > total               = status416 -- 416 Range Not Satisfiable
+      | (1 + upper - lower) < total = status206 -- 206 Partial Content
+      | otherwise                   = status200 -- 200 OK
+
+contentRangeH :: (Integral a, Show a) => a -> a -> Maybe a -> Header
+contentRangeH lower upper total =
+    ("Content-Range", toUtf8 headerValue)
+    where
+      headerValue   = rangeString <> "/" <> totalString :: Text
+      rangeString
+        | totalNotZero && fromInRange = show lower <> "-" <> show upper
+        | otherwise = "*"
+      totalString   = maybe "*" show total
+      totalNotZero  = maybe True (0 /=) total
+      fromInRange   = lower <= upper
@@ -0,0 +1,183 @@
+{-|
+Module      : PostgREST.Statements
+Description : PostgREST single SQL statements.
+
+This module constructs single SQL statements that can be parametrized and prepared.
+
+- It consumes the SqlQuery types generated by the QueryBuilder module.
+- It generates the body format and some headers of the final HTTP response.
+
+TODO: Currently, createReadStatement is not using prepared statements. See https://github.com/PostgREST/postgrest/issues/718.
+-}
+module PostgREST.Statements (
+    createWriteStatement
+  , createReadStatement
+  , callProcStatement
+  , createExplainStatement
+) where
+
+
+import           Control.Lens                    ((^?))
+import           Data.Aeson                      as JSON
+import qualified Data.Aeson.Lens                 as L
+import qualified Data.ByteString.Char8           as BS
+import           Data.Maybe
+import qualified Hasql.Decoders                  as HD
+import qualified Hasql.Encoders                  as HE
+import qualified Hasql.Statement                 as H
+import           PostgREST.Private.Common
+import           PostgREST.Private.QueryFragment
+import           PostgREST.Types
+import           Protolude                       hiding (cast,
+                                                  replace, toS)
+import           Protolude.Conv                  (toS)
+import           Text.InterpolatedString.Perl6   (qc)
+
+{-| The generic query result format used by API responses. The location header
+    is represented as a list of strings containing variable bindings like
+    @"k1=eq.42"@, or the empty list if there is no location header.
+-}
+type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString, Either Text [GucHeader])
+
+createWriteStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool ->
+                        PreferRepresentation -> [Text] -> PgVersion ->
+                        H.Statement ByteString ResultsWithCount
+createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys pgVer =
+  unicodeStatement sql (param HE.unknown) decodeStandard True
+ where
+  sql = [qc|
+      WITH
+      {sourceCTEName} AS ({mutateQuery})
+      SELECT
+        '' AS total_result_set,
+        pg_catalog.count(_postgrest_t) AS page_total,
+        {locF} AS header,
+        {bodyF} AS body,
+        {responseHeadersF pgVer} AS response_headers
+      FROM ({selectF}) _postgrest_t |]
+
+  locF =
+    if isInsert && rep `elem` [Full, HeadersOnly]
+      then unwords [
+        "CASE WHEN pg_catalog.count(_postgrest_t) = 1",
+          "THEN coalesce(" <> locationF pKeys <> ", " <> noLocationF <> ")",
+          "ELSE " <> noLocationF,
+        "END"]
+      else noLocationF
+
+  bodyF
+    | rep `elem` [None, HeadersOnly] = "''"
+    | asCsv = asCsvF
+    | wantSingle = asJsonSingleF
+    | otherwise = asJsonF
+
+  selectF
+    -- prevent using any of the column names in ?select= when no response is returned from the CTE
+    | rep `elem` [None, HeadersOnly] = "SELECT * FROM " <> sourceCTEName
+    | otherwise                      = selectQuery
+
+  decodeStandard :: HD.Result ResultsWithCount
+  decodeStandard =
+   fromMaybe (Nothing, 0, [], mempty, Right []) <$> HD.rowMaybe standardRow
+
+createReadStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion ->
+                       H.Statement () ResultsWithCount
+createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField pgVer =
+  unicodeStatement sql HE.noParams decodeStandard False
+ where
+  sql = [qc|
+      WITH
+      {sourceCTEName} AS ({selectQuery})
+      {countCTEF}
+      SELECT
+        {countResultF} AS total_result_set,
+        pg_catalog.count(_postgrest_t) AS page_total,
+        {noLocationF} AS header,
+        {bodyF} AS body,
+        {responseHeadersF pgVer} AS response_headers
+      FROM ( SELECT * FROM {sourceCTEName}) _postgrest_t |]
+
+  (countCTEF, countResultF) = countF countQuery countTotal
+
+  bodyF
+    | asCsv = asCsvF
+    | isSingle = asJsonSingleF
+    | isJust binaryField = asBinaryF $ fromJust binaryField
+    | otherwise = asJsonF
+
+  decodeStandard :: HD.Result ResultsWithCount
+  decodeStandard =
+    HD.singleRow standardRow
+
+{-| Read and Write api requests use a similar response format which includes
+    various record counts and possible location header. This is the decoder
+    for that common type of query.
+-}
+standardRow :: HD.Row ResultsWithCount
+standardRow = (,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
+                    <*> column header <*> column HD.bytea <*> column decodeGucHeaders
+  where
+    header = HD.array $ HD.dimension replicateM $ element HD.bytea
+
+type ProcResults = (Maybe Int64, Int64, ByteString, Either Text [GucHeader])
+
+callProcStatement :: Bool -> SqlQuery -> SqlQuery -> SqlQuery -> Bool ->
+                     Bool -> Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion ->
+                     H.Statement ByteString ProcResults
+callProcStatement returnsScalar callProcQuery selectQuery countQuery countTotal isSingle asCsv asBinary multObjects binaryField pgVer =
+  unicodeStatement sql (param HE.unknown) decodeProc True
+  where
+    sql = [qc|
+      WITH {sourceCTEName} AS ({callProcQuery})
+      {countCTEF}
+      SELECT
+        {countResultF} AS total_result_set,
+        pg_catalog.count(_postgrest_t) AS page_total,
+        {bodyF} AS body,
+        {responseHeadersF pgVer} AS response_headers
+      FROM ({selectQuery}) _postgrest_t;|]
+
+    (countCTEF, countResultF) = countF countQuery countTotal
+
+    bodyF
+     | returnsScalar = scalarBodyF
+     | isSingle     = asJsonSingleF
+     | asCsv = asCsvF
+     | isJust binaryField = asBinaryF $ fromJust binaryField
+     | otherwise = asJsonF
+
+    scalarBodyF
+     | asBinary    = asBinaryF "pgrst_scalar"
+     | multObjects = "json_agg(_postgrest_t.pgrst_scalar)::character varying"
+     | otherwise   = "(json_agg(_postgrest_t.pgrst_scalar)->0)::character varying"
+
+    decodeProc :: HD.Result ProcResults
+    decodeProc =
+      fromMaybe (Just 0, 0, mempty, Right []) <$> HD.rowMaybe procRow
+      where
+        procRow = (,,,) <$> nullableColumn HD.int8 <*> column HD.int8
+                        <*> column HD.bytea <*> column decodeGucHeaders
+
+createExplainStatement :: SqlQuery -> H.Statement () (Maybe Int64)
+createExplainStatement countQuery =
+  unicodeStatement sql HE.noParams decodeExplain False
+  where
+    sql = [qc| EXPLAIN (FORMAT JSON) {countQuery} |]
+    -- |
+    -- An `EXPLAIN (FORMAT JSON) select * from items;` output looks like this:
+    -- [{
+    --   "Plan": {
+    --     "Node Type": "Seq Scan", "Parallel Aware": false, "Relation Name": "items",
+    --     "Alias": "items", "Startup Cost": 0.00, "Total Cost": 32.60,
+    --     "Plan Rows": 2260,"Plan Width": 8} }]
+    -- We only obtain the Plan Rows here.
+    decodeExplain :: HD.Result (Maybe Int64)
+    decodeExplain =
+      let row = HD.singleRow $ column HD.bytea in
+      (^? L.nth 0 . L.key "Plan" .  L.key "Plan Rows" . L._Integral) <$> row
+
+unicodeStatement :: Text -> HE.Params a -> HD.Result b -> Bool -> H.Statement a b
+unicodeStatement = H.Statement . encodeUtf8
+
+decodeGucHeaders :: HD.Value (Either Text [GucHeader])
+decodeGucHeaders = first toS . JSON.eitherDecode . toS <$> HD.bytea
@@ -2,10 +2,14 @@
 Module      : PostgREST.Types
 Description : PostgREST common types and functions used by the rest of the modules
 -}
+{-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE DuplicateRecordFields #-}

 module PostgREST.Types where

+import Control.Lens.Getter (view)
+import Control.Lens.Tuple  (_1)
+
 import qualified Data.Aeson               as JSON
 import qualified Data.ByteString          as BS
 import qualified Data.ByteString.Internal as BS (c2w)
@@ -20,11 +24,12 @@ import Network.HTTP.Types.Header (Header, hContentType)
 import Data.Tree

 import PostgREST.RangeQuery (NonnegRange)
-import Protolude
+import Protolude            hiding (toS)
+import Protolude.Conv       (toS)

 -- | Enumeration of currently supported response content types
 data ContentType = CTApplicationJSON | CTSingularJSON
-                 | CTTextCSV | CTTextPlain | CTTextHtml
+                 | CTTextCSV | CTTextPlain
                 | CTOpenAPI | CTOctetStream
                 | CTAny | CTOther ByteString deriving (Show, Eq)

@@ -37,7 +42,6 @@ toMime :: ContentType -> ByteString
 toMime CTApplicationJSON = "application/json"
 toMime CTTextCSV         = "text/csv"
 toMime CTTextPlain       = "text/plain"
-toMime CTTextHtml        = "text/html"
 toMime CTOpenAPI         = "application/openapi+json"
 toMime CTSingularJSON    = "application/vnd.pgrst.object+json"
 toMime CTOctetStream     = "application/octet-stream"
@@ -50,7 +54,6 @@ decodeContentType ct = case BS.takeWhile (/= BS.c2w ';') ct of
  "application/json"                  -> CTApplicationJSON
  "text/csv"                          -> CTTextCSV
  "text/plain"                        -> CTTextPlain
-  "text/html"                         -> CTTextHtml
  "application/openapi+json"          -> CTOpenAPI
  "application/vnd.pgrst.object+json" -> CTSingularJSON
  "application/vnd.pgrst.object"      -> CTSingularJSON
@@ -58,22 +61,53 @@ decodeContentType ct = case BS.takeWhile (/= BS.c2w ';') ct of
  "*/*"                               -> CTAny
  ct'                                 -> CTOther ct'

-- | ContentTypes that can get a raw/unwrapped response
-rawContentTypes :: [ContentType]
-rawContentTypes = [CTOctetStream, CTTextPlain, CTTextHtml]
+-- | A SQL query that can be executed independently
+type SqlQuery = Text
+
+-- | A part of a SQL query that cannot be executed independently
+type SqlFragment = Text

 data PreferResolution = MergeDuplicates | IgnoreDuplicates deriving Eq
 instance Show PreferResolution where
  show MergeDuplicates  = "resolution=merge-duplicates"
  show IgnoreDuplicates = "resolution=ignore-duplicates"

+-- | How to return the mutated data. From https://tools.ietf.org/html/rfc7240#section-4.2
+data PreferRepresentation = Full        -- ^ Return the body plus the Location header(in case of POST).
+                          | HeadersOnly -- ^ Return the Location header(in case of POST). This needs a SELECT privilege on the pk.
+                          | None        -- ^ Return nothing from the mutated data.
+                          deriving Eq
+instance Show PreferRepresentation where
+  show Full        = "return=representation"
+  show None        = "return=minimal"
+  show HeadersOnly = mempty
+
+data PreferParameters
+  = SingleObject    -- ^ Pass all parameters as a single json object to a stored procedure
+  | MultipleObjects -- ^ Pass an array of json objects as params to a stored procedure
+  deriving Eq
+
+instance Show PreferParameters where
+  show SingleObject    = "params=single-object"
+  show MultipleObjects = "params=multiple-objects"
+
+data PreferCount
+  = ExactCount     -- ^ exact count(slower)
+  | PlannedCount   -- ^ PostgreSQL query planner rows count guess. Done by using EXPLAIN {query}.
+  | EstimatedCount -- ^ use the query planner rows if the count is superior to max-rows, otherwise get the exact count.
+  deriving Eq
+
+instance Show PreferCount where
+  show ExactCount     = "count=exact"
+  show PlannedCount   = "count=planned"
+  show EstimatedCount = "count=estimated"
+
 data DbStructure = DbStructure {
  dbTables      :: [Table]
 , dbColumns     :: [Column]
 , dbRelations   :: [Relation]
 , dbPrimaryKeys :: [PrimaryKey]
-- ProcDescription is a list because a function can be overloaded
-, dbProcs       :: M.HashMap Text [ProcDescription]
+, dbProcs       :: ProcsMap
 , pgVersion     :: PgVersion
 } deriving (Show, Eq)

@@ -99,7 +133,8 @@ data ProcVolatility = Volatile | Stable | Immutable
  deriving (Eq, Show, Ord)

 data ProcDescription = ProcDescription {
-  pdName        :: Text
+  pdSchema      :: Schema
+, pdName        :: Text
 , pdDescription :: Maybe Text
 , pdArgs        :: [PgArg]
 , pdReturnType  :: RetType
@@ -108,18 +143,23 @@ data ProcDescription = ProcDescription {

 -- Order by least number of args in the case of overloaded functions
 instance Ord ProcDescription where
-  ProcDescription name1 des1 args1 rt1 vol1 `compare` ProcDescription name2 des2 args2 rt2 vol2
-    | name1 == name2 && length args1 < length args2  = LT
-    | name1 == name2 && length args1 > length args2  = GT
-    | otherwise = (name1, des1, args1, rt1, vol1) `compare` (name2, des2, args2, rt2, vol2)
+  ProcDescription schema1 name1 des1 args1 rt1 vol1 `compare` ProcDescription schema2 name2 des2 args2 rt2 vol2
+    | schema1 == schema2 && name1 == name2 && length args1 < length args2  = LT
+    | schema2 == schema2 && name1 == name2 && length args1 > length args2  = GT
+    | otherwise = (schema1, name1, des1, args1, rt1, vol1) `compare` (schema2, name2, des2, args2, rt2, vol2)
+
+-- | A map of all procs, all of which can be overloaded(one entry will have more than one ProcDescription).
+-- | It uses a HashMap for a faster lookup.
+type ProcsMap = M.HashMap QualifiedIdentifier [ProcDescription]

 {-|
  Search a pg procedure by its parameters. Since a function can be overloaded, the name is not enough to find it.
  An overloaded function can have a different volatility or even a different return type.
+  Ideally, handling overloaded functions should be left to pg itself. But we need to know certain proc attributes in advance.
 -}
-findProc :: QualifiedIdentifier -> S.Set Text -> Bool -> M.HashMap Text [ProcDescription] -> Maybe ProcDescription
+findProc :: QualifiedIdentifier -> S.Set Text -> Bool -> ProcsMap -> Maybe ProcDescription
 findProc qi payloadKeys paramsAsSingleObject allProcs =
-  case M.lookup (qiName qi) allProcs of
+  case M.lookup qi allProcs of
    Nothing     -> Nothing
    Just [proc] -> Just proc           -- if it's not an overloaded function then immediately get the ProcDescription
    Just procs  -> find matches procs  -- Handle overloaded functions case
@@ -141,10 +181,19 @@ specifiedProcArgs keys proc =
  in
  (\k -> fromMaybe (PgArg k "text" True) (find ((==) k . pgaName) args)) <$> S.toList keys

+procReturnsScalar :: ProcDescription -> Bool
+procReturnsScalar proc = case proc of
+  ProcDescription{pdReturnType = (Single (Scalar _))} -> True
+  _                                                   -> False
+
+procTableName :: ProcDescription -> Maybe TableName
+procTableName proc = case pdReturnType proc of
+  SetOf  (Composite qi) -> Just $ qiName qi
+  Single (Composite qi) -> Just $ qiName qi
+  _                     -> Nothing
+
 type Schema = Text
 type TableName = Text
-type SqlQuery = Text
-type SqlFragment = Text

 data Table = Table {
  tableSchema      :: Schema
@@ -156,6 +205,9 @@ data Table = Table {
 instance Eq Table where
  Table{tableSchema=s1,tableName=n1} == Table{tableSchema=s2,tableName=n2} = s1 == s2 && n1 == n2

+tableQi :: Table -> QualifiedIdentifier
+tableQi Table{tableSchema=s, tableName=n} = QualifiedIdentifier s n
+
 newtype ForeignKey = ForeignKey { fkCol :: Column } deriving (Show, Eq, Ord)

 data Column =
@@ -177,8 +229,8 @@ data Column =
 instance Eq Column where
  Column{colTable=t1,colName=n1} == Column{colTable=t2,colName=n2} = t1 == t2 && n1 == n2

-- | A view column that refers to a table column
-type Synonym = (Column, ViewColumn)
+-- | The source table column a view column refers to
+type SourceColumn = (Column, ViewColumn)
 type ViewColumn = Column

 data PrimaryKey = PrimaryKey {
@@ -209,42 +261,56 @@ data OrderTerm = OrderTerm {
 data QualifiedIdentifier = QualifiedIdentifier {
  qiSchema :: Schema
 , qiName   :: TableName
-} deriving (Show, Eq, Ord)
+} deriving (Show, Eq, Ord, Generic)
+instance Hashable QualifiedIdentifier

+-- | The relationship [cardinality](https://en.wikipedia.org/wiki/Cardinality_(data_modeling)).
+-- | TODO: missing one-to-one
+data Cardinality = O2M -- ^ one-to-many,  previously known as Parent
+                 | M2O -- ^ many-to-one,  previously known as Child
+                 | M2M -- ^ many-to-many, previously known as Many
+                 deriving Eq
+instance Show Cardinality where
+  show O2M = "o2m"
+  show M2O = "m2o"
+  show M2M = "m2m"

-data RelationType = Child | Parent | Many | Root deriving (Show, Eq)
+type ConstraintName = Text

 {-|
-  The name 'Relation' here is used with the meaning
-  "What is the relation between the current node and the parent node".
-  It has nothing to do with PostgreSQL referring to tables/views as relations.
-  The order of the relColumns and relFColumns should be maintained to get
-  the join conditions right.
+  "Relation"ship between two tables.
+  The order of the relColumns and relFColumns should be maintained to get the join conditions right.
  TODO merge relColumns and relFColumns to a tuple or Data.Bimap
 -}
 data Relation = Relation {
-  relTable     :: Table
-, relColumns   :: [Column]
-, relFTable    :: Table
-, relFColumns  :: [Column]
-, relType      :: RelationType
-- The Link attrs are used when RelationType == Many
-, relLinkTable :: Maybe Table
-, relLinkCols1 :: Maybe [Column]
-, relLinkCols2 :: Maybe [Column]
+  relTable      :: Table
+, relColumns    :: [Column]
+, relConstraint :: Maybe ConstraintName -- ^ Just on O2M/M2O, Nothing on M2M
+, relFTable     :: Table
+, relFColumns   :: [Column]
+, relType       :: Cardinality
+, relJunction   :: Maybe Junction -- ^ Junction for M2M Cardinality
 } deriving (Show, Eq)

-isSelfJoin :: Relation -> Bool
-isSelfJoin r = relType r /= Root && relTable r == relFTable r
+-- | Junction table on an M2M relationship
+data Junction = Junction {
+  junTable       :: Table
+, junConstraint1 :: Maybe ConstraintName
+, junCols1       :: [Column]
+, junConstraint2 :: Maybe ConstraintName
+, junCols2       :: [Column]
+} deriving (Show, Eq)
+
+isSelfReference :: Relation -> Bool
+isSelfReference r = relTable r == relFTable r

 data PayloadJSON =
  -- | Cached attributes of a JSON payload
  ProcessedJSON {
    -- | This is the raw ByteString that comes from the request body.
    -- We cache this instead of an Aeson Value because it was detected that for large payloads the encoding
-    -- had high memory usage, see #1005 for more details
+    -- had high memory usage, see https://github.com/PostgREST/postgrest/pull/1005 for more details
    pjRaw  :: BL.ByteString
-  , pjType :: PJType
    -- | Keys of the object or if it's an array these keys are guaranteed to be the same across all its objects
  , pjKeys :: S.Set Text
  }|
@@ -287,7 +353,8 @@ ftsOperators :: M.HashMap Operator SqlFragment
 ftsOperators = M.fromList [
  ("fts", "@@ to_tsquery"),
  ("plfts", "@@ plainto_tsquery"),
-  ("phfts", "@@ phraseto_tsquery")
+  ("phfts", "@@ phraseto_tsquery"),
+  ("wfts", "@@ websearch_to_tsquery")
  ]

 data OpExpr = OpExpr Bool Operation deriving (Eq, Show)
@@ -338,24 +405,33 @@ type RpcQParam = (Text, Text)
  Custom guc header, it's obtained by parsing the json in a:
  `SET LOCAL "response.headers" = '[{"Set-Cookie": ".."}]'
 -}
-newtype GucHeader = GucHeader (Text, Text)
+newtype GucHeader = GucHeader (CI.CI ByteString, ByteString)
+  deriving (Show, Eq)

 instance JSON.FromJSON GucHeader where
  parseJSON (JSON.Object o) = case headMay (M.toList o) of
-    Just (k, JSON.String s) | M.size o == 1 -> pure $ GucHeader (k, s)
+    Just (k, JSON.String s) | M.size o == 1 -> pure $ GucHeader (CI.mk $ toS k, toS s)
                            | otherwise     -> mzero
    _ -> mzero
  parseJSON _          = mzero

-toHeaders :: [GucHeader] -> [Header]
-toHeaders = map $ \(GucHeader (k, v)) -> (CI.mk $ toS k, toS v)
+unwrapGucHeader :: GucHeader -> Header
+unwrapGucHeader (GucHeader (k, v)) = (k, v)
+
+-- | Add headers not already included to allow the user to override them instead of duplicating them
+addHeadersIfNotIncluded :: [Header] -> [Header] -> [Header]
+addHeadersIfNotIncluded newHeaders initialHeaders =
+  filter (\(nk, _) -> isNothing $ find (\(ik, _) -> ik == nk) initialHeaders) newHeaders ++
+  initialHeaders

 {-|
  This type will hold information about which particular 'Relation' between two tables to choose when there are multiple ones.
  Specifically, it will contain the name of the foreign key or the join table in many to many relations.
 -}
-type RelationDetail = Text
-type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe RelationDetail)
+type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe EmbedHint)
+-- | Disambiguates an embedding operation when there's multiple relationships between two tables.
+-- | Can be the name of a foreign key constraint, column name or the junction in an m2m relationship.
+type EmbedHint = Text
 -- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path ["clients", "projects"]
 type EmbedPath = [Text]
 data Filter = Filter { field::Field, opExpr::OpExpr } deriving (Show, Eq)
@@ -364,11 +440,11 @@ data JoinCondition = JoinCondition (QualifiedIdentifier, FieldName)

 data ReadQuery = Select {
    select         :: [SelectItem]
-  , from           :: TableName
+  , from           :: QualifiedIdentifier
 -- | A table alias is used in case of self joins
  , fromAlias      :: Maybe Alias
 -- | Only used for Many to Many joins. Parent and Child joins use explicit joins.
-  , implicitJoins  :: [TableName]
+  , implicitJoins  :: [QualifiedIdentifier]
  , where_         :: [LogicTree]
  , joinConditions :: [JoinCondition]
  , order          :: [OrderTerm]
@@ -377,31 +453,35 @@ data ReadQuery = Select {

 data MutateQuery =
  Insert {
-    in_        :: TableName
+    in_        :: QualifiedIdentifier
  , insCols    :: S.Set FieldName
  , onConflict :: Maybe (PreferResolution, [FieldName])
  , where_     :: [LogicTree]
  , returning  :: [FieldName]
  }|
  Update {
-    in_       :: TableName
+    in_       :: QualifiedIdentifier
  , updCols   :: S.Set FieldName
  , where_    :: [LogicTree]
  , returning :: [FieldName]
  }|
  Delete {
-    in_       :: TableName
+    in_       :: QualifiedIdentifier
  , where_    :: [LogicTree]
  , returning :: [FieldName]
  } deriving (Show, Eq)

-data DbRequest = DbRead ReadRequest | DbMutate MutateRequest
 type ReadRequest = Tree ReadNode
-type ReadNode = (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail, Depth))
-- Depth of the ReadRequest tree
-type Depth = Integer
 type MutateRequest = MutateQuery

+type ReadNode = (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe EmbedHint, Depth))
+type Depth = Integer
+
+-- First level FieldNames(e.g get a,b from /table?select=a,b,other(c,d))
+fstFieldNames :: ReadRequest -> [FieldName]
+fstFieldNames (Node (sel, _) _) =
+  fst . view _1 <$> select sel
+
 data PgVersion = PgVersion {
  pgvNum  :: Int32
 , pgvName :: Text
@@ -426,19 +506,29 @@ pgVersion96 = PgVersion 90600 "9.6"
 pgVersion100 :: PgVersion
 pgVersion100 = PgVersion 100000 "10"

+pgVersion109 :: PgVersion
+pgVersion109 = PgVersion 100009 "10.9"
+
+pgVersion110 :: PgVersion
+pgVersion110 = PgVersion 110000 "11.0"
+
 pgVersion112 :: PgVersion
 pgVersion112 = PgVersion 110002 "11.2"

+pgVersion114 :: PgVersion
+pgVersion114 = PgVersion 110004 "11.4"
+
+pgVersion121 :: PgVersion
+pgVersion121 = PgVersion 120001 "12.1"
+
 sourceCTEName :: SqlFragment
-sourceCTEName = "pg_source"
+sourceCTEName = "pgrst_source"

 -- | full jspath, e.g. .property[0].attr.detail
 type JSPath = [JSPathExp]
 -- | jspath expression, e.g. .property, .property[0] or ."property-dash"
 data JSPathExp = JSPKey Text | JSPIdx Int deriving (Eq, Show)

-
-
 -- | Current database connection status data ConnectionStatus
 data ConnectionStatus
  = NotConnected
@@ -1,18 +1,11 @@
-# stack.yaml is used for circle-ci tests. Profiling build fails on circleci
-# with GHC 8.6, so we build with 8.4 for now.
-
-resolver: lts-12.26
-extra-deps:
- Ranged-sets-0.4.0
- configurator-pg-0.1.0.3
- http-types-0.12.3
- hasql-1.4
- hasql-pool-0.5.1
- hasql-transaction-0.7.2
- text-builder-0.6.5.1
- deferred-folds-0.9.10.1
- primitive-0.6.4.0
-ghc-options:
-  postgrest: -O2 -Werror -Wall -fwarn-identities -fno-warn-redundant-constraints
+# stack is used for circleci and appveyor CI builds
+resolver: lts-15.8
 nix:
  packages: [pcre, pkgconfig, postgresql, zlib]
+  # disable pure by default so that the test enviroment can be passed 
+  pure: false
+extra-deps:
+- configurator-pg-0.2.2@sha256:8f3f7c66dd4a53852283c70806ebc101a7219f8b01c3e80c5130e9749c998dc8,2987
+- hspec-wai-json-0.10.1@sha256:67b405c38f0a9e2771480c8d3ecd8aeb8d8776a35d3b2906cb1b76c9538617e4,1629
+- interpolatedstring-perl6-1.0.2@sha256:7ce49c8a69a2a1b89c001ed79db2aab656ffd0faf2a7a701a553b6deb5c8ba7f,1073
+- protolude-0.3.0@sha256:8361b811b420585b122a7ba715aa5923834db6e8c36309bf267df2dbf66b95ef,2693
@@ -0,0 +1,40 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages:
+- completed:
+    hackage: configurator-pg-0.2.2@sha256:8f3f7c66dd4a53852283c70806ebc101a7219f8b01c3e80c5130e9749c998dc8,2987
+    pantry-tree:
+      size: 2462
+      sha256: a669366632e19f396dfe52599d54414b9c92d5664ea4391c2c797be271f9aa0e
+  original:
+    hackage: configurator-pg-0.2.2@sha256:8f3f7c66dd4a53852283c70806ebc101a7219f8b01c3e80c5130e9749c998dc8,2987
+- completed:
+    hackage: hspec-wai-json-0.10.1@sha256:67b405c38f0a9e2771480c8d3ecd8aeb8d8776a35d3b2906cb1b76c9538617e4,1629
+    pantry-tree:
+      size: 349
+      sha256: fb9e89b79cde3276baa484c860c6b9eeebdbc1a5c43301293351a25bc4c08e87
+  original:
+    hackage: hspec-wai-json-0.10.1@sha256:67b405c38f0a9e2771480c8d3ecd8aeb8d8776a35d3b2906cb1b76c9538617e4,1629
+- completed:
+    hackage: interpolatedstring-perl6-1.0.2@sha256:7ce49c8a69a2a1b89c001ed79db2aab656ffd0faf2a7a701a553b6deb5c8ba7f,1073
+    pantry-tree:
+      size: 300
+      sha256: f7f0b06c58db814d1f12ed6f4f4cb67ff8c72e51da61c04db12c2aedb896542e
+  original:
+    hackage: interpolatedstring-perl6-1.0.2@sha256:7ce49c8a69a2a1b89c001ed79db2aab656ffd0faf2a7a701a553b6deb5c8ba7f,1073
+- completed:
+    hackage: protolude-0.3.0@sha256:8361b811b420585b122a7ba715aa5923834db6e8c36309bf267df2dbf66b95ef,2693
+    pantry-tree:
+      size: 1644
+      sha256: babf32b414f25f790b7a4ce6bae5c960bc51a11a289e7c47335b222e6762560c
+  original:
+    hackage: protolude-0.3.0
+snapshots:
+- completed:
+    size: 492015
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/15/8.yaml
+    sha256: 926bc3d70249dd0ba05277ff00943c0addb35b627cb641752669e7cf771310d0
+  original: lts-15.8
@@ -4,7 +4,7 @@ ENV PATH /root/.local/bin:$PATH

 RUN apt-get update \
    && apt-get install -y wget libpq-dev pkg-config libpcre3 libpcre3-dev \
-       postgresql-client debconf locales \
+       postgresql-client debconf locales build-essential libffi-dev libgmp-dev git \
    && apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
    && echo 'en_US.UTF-8 UTF-8' > /etc/locale.gen \
    && locale-gen \
@@ -7,12 +7,12 @@ import Test.Hspec
 import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON

-import Protolude  hiding (get)
+import PostgREST.Types (PgVersion, pgVersion112)
+import Protolude       hiding (get)
 import SpecHelper

-
-spec :: SpecWith Application
-spec =
+spec :: PgVersion -> SpecWith ((), Application)
+spec actualPgVersion =
  describe "and/or params used for complex boolean logic" $ do
    context "used with GET" $ do
      context "or param" $ do
@@ -80,6 +80,19 @@ spec =
              {"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4" },
              {"text_search_vector": "'art':4 'spass':5 'unmog':7"}
            ]|] { matchHeaders = [matchContentTypeJson] }
+
+        when (actualPgVersion >= pgVersion112) $
+          it "can handle wfts (websearch_to_tsquery)" $
+            get "/tsearch?or=(text_search_vector.plfts(german).Art,text_search_vector.plfts(french).amusant,text_search_vector.not.wfts(english).impossible)"
+            `shouldRespondWith`
+              [json|[
+                     {"text_search_vector": "'also':2 'fun':3 'possibl':8" },
+                     {"text_search_vector": "'ate':3 'cat':2 'fat':1 'rat':4" },
+                     {"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4" },
+                     {"text_search_vector": "'art':4 'spass':5 'unmog':7" }
+              ]|]
+              { matchHeaders = [matchContentTypeJson] }
+
        it "can handle cs and cd" $
          get "/entities?or=(arr.cs.{1,2,3},arr.cd.{1})&select=id" `shouldRespondWith`
            [json|[{ "id": 1 },{ "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
@@ -114,6 +127,34 @@ spec =
          get "/ranges?range=adj.(3,10]&select=id" `shouldRespondWith`
            [json|[{ "id": 1 }]|] { matchHeaders = [matchContentTypeJson] }

+        it "can handle array operators" $ do
+          get "/entities?arr=eq.{1,2,3}&select=id" `shouldRespondWith`
+            [json|[{ "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=neq.{1,2}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=lt.{2,3}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=lt.{2,0}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=gt.{1,1}&select=id" `shouldRespondWith`
+            [json|[{ "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=gt.{3}&select=id" `shouldRespondWith`
+            [json|[]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=lte.{2,1}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=lte.{1,2,3}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=lte.{1,2}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=cs.{1,2}&select=id" `shouldRespondWith`
+            [json|[{ "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=cd.{1,2,6}&select=id" `shouldRespondWith`
+            [json|[{ "id": 1 }, { "id": 2 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=ov.{3}&select=id" `shouldRespondWith`
+            [json|[{ "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/entities?arr=ov.{2,3}&select=id" `shouldRespondWith`
+            [json|[{ "id": 2 }, { "id": 3 }]|] { matchHeaders = [matchContentTypeJson] }
+
        context "operators with not" $ do
          it "eq, cs, like can be negated" $
            get "/entities?and=(arr.not.cs.{1,2,3},and(id.not.eq.2,name.not.like.*3))&select=id" `shouldRespondWith`
@@ -11,7 +11,7 @@ import Protolude
 import SpecHelper
 -- }}}

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "server started with asymmetric JWK" $

  -- this test will stop working 9999999999s after the UNIX EPOCH
@@ -11,7 +11,7 @@ import Protolude  hiding (get)
 import SpecHelper
 -- }}}

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "test handling of aud claims in JWT" $ do

  -- this test will stop working 9999999999s after the UNIX EPOCH
@@ -12,7 +12,7 @@ import PostgREST.Types (PgVersion, pgVersion112)
 import Protolude       hiding (get)
 import SpecHelper

-spec :: PgVersion -> SpecWith Application
+spec :: PgVersion -> SpecWith ((), Application)
 spec actualPgVersion = describe "authorization" $ do
  let single = ("Accept","application/vnd.pgrst.object+json")

@@ -117,11 +117,11 @@ spec actualPgVersion = describe "authorization" $ do
  it "hides tables from users with invalid JWT" $ do
    let auth = authHeaderJWT "ey9zdGdyZXN0X3Rlc3RfYXV0aG9yIiwiaWQiOiJqZG9lIn0.y4vZuu1dDdwAl0-S00MCRWRYMlJ5YAMSir6Es6WtWx0"
    request methodGet "/authors_only" [auth] ""
-      `shouldRespondWith` [json| {"message":"JWSError (CompactDecodeError \"expected 3 parts, got 2\")"} |]
+      `shouldRespondWith` [json| {"message":"JWSError (CompactDecodeError Invalid number of parts: Expected 3 parts; got 2)"} |]
        { matchStatus = 401
        , matchHeaders = [
            "WWW-Authenticate" <:>
-            "Bearer error=\"invalid_token\", error_description=\"JWSError (CompactDecodeError \\\"expected 3 parts, got 2\\\")\""
+            "Bearer error=\"invalid_token\", error_description=\"JWSError (CompactDecodeError Invalid number of parts: Expected 3 parts; got 2)\""
          ]
        }

@@ -11,7 +11,7 @@ import Protolude
 import SpecHelper
 -- }}}

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "server started with binary JWT secret" $

  -- this test will stop working 9999999999s after the UNIX EPOCH
@@ -5,7 +5,6 @@
 module Feature.ConcurrentSpec where

 import Control.Concurrent.Async (mapConcurrently)
-import Control.Monad            (void)
 import Network.Wai              (Application)

 import Control.Monad.Base
@@ -19,9 +18,9 @@ import Test.Hspec.Wai.JSON

 import Protolude hiding (get)

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
-  describe "Queryiny in parallel" $
+  describe "Querying in parallel" $
    it "should not raise 'transaction in progress' error" $
      raceTest 10 $
        get "/fakefake"
@@ -35,13 +34,13 @@ spec =
          , matchHeaders = []
          }

-raceTest :: Int -> WaiExpectation -> WaiExpectation
+raceTest :: Int -> WaiExpectation st -> WaiExpectation st
 raceTest times = liftBaseDiscard go
 where
  go test = void $ mapConcurrently (const test) [1..times]

-instance MonadBaseControl IO WaiSession where
-  type StM WaiSession a = StM Session a
+instance MonadBaseControl IO (WaiSession st) where
+  type StM (WaiSession st) a = StM Session a
  liftBaseWith f = WaiSession $
    liftBaseWith $ \runInBase ->
      f $ \k -> runInBase (unWaiSession k)
@@ -49,5 +48,5 @@ instance MonadBaseControl IO WaiSession where
  {-# INLINE liftBaseWith #-}
  {-# INLINE restoreM #-}

-instance MonadBase IO WaiSession where
+instance MonadBase IO (WaiSession st) where
  liftBase = liftIO
@@ -14,7 +14,7 @@ import Protolude
 import SpecHelper
 -- }}}

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "CORS" $ do
    let preflightHeaders = [
@@ -5,11 +5,12 @@ import Network.Wai (Application)
 import Network.HTTP.Types
 import Test.Hspec
 import Test.Hspec.Wai
+import Test.Hspec.Wai.JSON
 import Text.Heredoc

 import Protolude hiding (get)

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "Deleting" $ do
    context "existing record" $ do
@@ -26,17 +27,32 @@ spec =
          { matchStatus  = 200
          , matchHeaders = ["Content-Range" <:> "*/1"]
          }
+
+      it "ignores ?select= when return not set or return=minimal" $ do
+        request methodDelete "/items?id=eq.3&select=id" [] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 204
+          , matchHeaders = ["Content-Range" <:> "*/*"]
+          }
+        request methodDelete "/items?id=eq.3&select=id" [("Prefer", "return=minimal")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 204
+          , matchHeaders = ["Content-Range" <:> "*/*"]
+          }
+
      it "returns the deleted item and shapes the response" $
        request methodDelete "/complex_items?id=eq.2&select=id,name" [("Prefer", "return=representation")] ""
          `shouldRespondWith` [str|[{"id":2,"name":"Two"}]|]
          { matchStatus  = 200
          , matchHeaders = ["Content-Range" <:> "*/*"]
          }
+
      it "can rename and cast the selected columns" $
        request methodDelete "/complex_items?id=eq.3&select=ciId:id::text,ciName:name" [("Prefer", "return=representation")] ""
          `shouldRespondWith` [str|[{"ciId":"3","ciName":"Three"}]|]
+
      it "can embed (parent) entities" $
-        request methodDelete "/tasks?id=eq.8&select=id,name,project(id)" [("Prefer", "return=representation")] ""
+        request methodDelete "/tasks?id=eq.8&select=id,name,project:projects(id)" [("Prefer", "return=representation")] ""
          `shouldRespondWith` [str|[{"id":8,"name":"Code OSX","project":{"id":4}}]|]
          { matchStatus  = 200
          , matchHeaders = ["Content-Range" <:> "*/*"]
@@ -62,3 +78,24 @@ spec =
    context "totally unknown route" $
      it "fails with 404" $
        request methodDelete "/foozle?id=eq.101" [] "" `shouldRespondWith` 404
+
+    context "table with limited privileges" $ do
+      it "fails deleting the row when return=representation and selecting all the columns" $
+        request methodDelete "/app_users?id=eq.1" [("Prefer", "return=representation")] mempty
+            `shouldRespondWith` 401
+
+      it "succeeds deleting the row when return=representation and selecting only the privileged columns" $
+        request methodDelete "/app_users?id=eq.1&select=id,email" [("Prefer", "return=representation")]
+          [json| { "password": "passxyz" } |]
+            `shouldRespondWith` [json|[ { "id": 1, "email": "test@123.com" } ]|]
+            { matchStatus  = 200
+            , matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+      it "suceeds deleting the row with no explicit select when using return=minimal" $
+        request methodDelete "/app_users?id=eq.2" [("Prefer", "return=minimal")] mempty
+            `shouldRespondWith` 204
+
+      it "suceeds deleting the row with no explicit select by default" $
+        request methodDelete "/app_users?id=eq.3" [] mempty
+            `shouldRespondWith` 204
@@ -0,0 +1,434 @@
+module Feature.EmbedDisambiguationSpec where
+
+import Network.Wai (Application)
+
+import Test.Hspec          hiding (pendingWith)
+import Test.Hspec.Wai
+import Test.Hspec.Wai.JSON
+import Text.Heredoc
+
+import Protolude  hiding (get)
+import SpecHelper
+
+spec :: SpecWith ((), Application)
+spec =
+  describe "resource embedding disambiguation" $ do
+    context "ambiguous requests that give 300 Multiple Choices" $ do
+      it "errs when there's a table and view that point to the same fk" $
+        get "/message?select=id,body,sender(name,sent)" `shouldRespondWith`
+          [json|
+            {
+              "details": [
+                {
+                    "cardinality": "m2o",
+                    "relationship": "message_sender_fkey[sender][id]",
+                    "origin": "test.message",
+                    "target": "test.person"
+                },
+                {
+                    "cardinality": "m2o",
+                    "relationship": "message_sender_fkey[sender][id]",
+                    "origin": "test.message",
+                    "target": "test.person_detail"
+                }
+              ],
+              "hint": "By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)",
+              "message": "More than one relationship was found for message and sender"
+            }
+          |]
+          { matchStatus  = 300
+          , matchHeaders = [matchContentTypeJson]
+          }
+
+      it "errs when there are o2m and m2m cardinalities to the target table" $
+        get "/sites?select=*,big_projects(*)" `shouldRespondWith`
+          [json|
+            {
+              "details": [
+                {
+                  "cardinality": "m2o",
+                  "relationship": "main_project[main_project_id][big_project_id]",
+                  "origin": "test.sites",
+                  "target": "test.big_projects"
+                },
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.jobs[jobs_site_id_fkey][jobs_big_project_id_fkey]",
+                  "origin": "test.sites",
+                  "target": "test.big_projects"
+                },
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.main_jobs[jobs_site_id_fkey][jobs_big_project_id_fkey]",
+                  "origin": "test.sites",
+                  "target": "test.big_projects"
+                }
+              ],
+              "hint": "By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)",
+              "message": "More than one relationship was found for sites and big_projects"
+            }
+          |]
+          { matchStatus  = 300
+          , matchHeaders = [matchContentTypeJson]
+          }
+
+      it "errs on an ambiguous embed that has a circular reference" $
+        get "/agents?select=*,departments(*)" `shouldRespondWith`
+          [json|
+            {
+              "details": [
+                {
+                    "cardinality": "m2o",
+                    "relationship": "agents_department_id_fkey[department_id][id]",
+                    "origin": "test.agents",
+                    "target": "test.departments"
+                },
+                {
+                    "cardinality": "o2m",
+                    "relationship": "departments_head_id_fkey[id][head_id]",
+                    "origin": "test.agents",
+                    "target": "test.departments"
+                }
+              ],
+              "hint": "By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)",
+              "message": "More than one relationship was found for agents and departments"
+            }
+           |]
+          { matchStatus  = 300
+          , matchHeaders = [matchContentTypeJson]
+          }
+
+      it "errs when there are more than two fks on a junction table(currently impossible to disambiguate, only choice is to split the table)" $
+        -- We have 4 possibilities for doing the junction JOIN here.
+        -- This could be solved by specifying two additional fks, like whatev_projects!fk1!fk2(*)
+        -- If the need arises this capability can be added later without causing a breaking change
+        get "/whatev_sites?select=*,whatev_projects(*)" `shouldRespondWith`
+          [json|
+            {
+              "details": [
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.whatev_jobs[whatev_jobs_site_id_1_fkey][whatev_jobs_project_id_1_fkey]",
+                  "origin": "test.whatev_sites",
+                  "target": "test.whatev_projects"
+                },
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.whatev_jobs[whatev_jobs_site_id_1_fkey][whatev_jobs_project_id_2_fkey]",
+                  "origin": "test.whatev_sites",
+                  "target": "test.whatev_projects"
+                },
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.whatev_jobs[whatev_jobs_site_id_2_fkey][whatev_jobs_project_id_1_fkey]",
+                  "origin": "test.whatev_sites",
+                  "target": "test.whatev_projects"
+                },
+                {
+                  "cardinality": "m2m",
+                  "relationship": "test.whatev_jobs[whatev_jobs_site_id_2_fkey][whatev_jobs_project_id_2_fkey]",
+                  "origin": "test.whatev_sites",
+                  "target": "test.whatev_projects"
+                }
+              ],
+              "hint": "By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)",
+              "message": "More than one relationship was found for whatev_sites and whatev_projects"
+            }
+          |]
+          { matchStatus  = 300
+          , matchHeaders = [matchContentTypeJson]
+          }
+
+    context "disambiguating requests with embed hints" $ do
+
+      context "using FK to specify the relationship" $ do
+        it "can embed by FK name" $
+          get "/projects?id=in.(1,3)&select=id,name,client(id,name)" `shouldRespondWith`
+            [json|[{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client":{"id":2,"name":"Apple"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can embed by FK name and select the FK column at the same time" $
+          get "/projects?id=in.(1,3)&select=id,name,client_id,client(id,name)" `shouldRespondWith`
+            [json|[{"id":1,"name":"Windows 7","client_id":1,"client":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":2,"client":{"id":2,"name":"Apple"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can embed parent with view!fk and grandparent by using fk" $
+          get "/tasks?id=eq.1&select=id,name,projects_view!project(id,name,client(id,name))" `shouldRespondWith`
+            [str|[{"id":1,"name":"Design w7","projects_view":{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}}}]|]
+
+        it "can embed by using a composite FK name" $
+          get "/unit_workdays?select=unit_id,day,fst_shift(car_id,schedule(name)),snd_shift(camera_id,schedule(name))" `shouldRespondWith`
+            [json| [
+              {
+                "day": "2019-12-02",
+                "fst_shift": {
+                    "car_id": "CAR-349",
+                    "schedule": {
+                        "name": "morning"
+                    }
+                },
+                "snd_shift": {
+                    "camera_id": "CAM-123",
+                    "schedule": {
+                        "name": "night"
+                    }
+                },
+                "unit_id": 1
+              }
+            ] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds by using two fks pointing to the same table" $
+          get "/orders?id=eq.1&select=id, name, billing(address), shipping(address)" `shouldRespondWith`
+            [json|[{"id":1,"name":"order 1","billing":{"address": "address 1"},"shipping":{"address": "address 2"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "fails if the fk is not known" $
+          get "/message?select=id,sender:person!space(name)&id=lt.4" `shouldRespondWith`
+            [json|{"message":"Could not find foreign keys between these entities. No relationship found between message and person"}|]
+            { matchStatus = 400
+            , matchHeaders = [matchContentTypeJson] }
+
+        it "can request a parent with fk" $
+          get "/comments?select=content,user(name)" `shouldRespondWith`
+            [json|[ { "content": "Needs to be delivered ASAP", "user": { "name": "Angela Martin" } } ]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can request two parents with fks" $
+          get "/articleStars?select=createdAt,article(owner),user(name)&limit=1" `shouldRespondWith`
+            [json|[{"createdAt":"2015-12-08T04:22:57.472738","article":{"owner": "postgrest_test_authenticator"},"user":{"name": "Angela Martin"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can specify a view!fk" $
+          get "/message?select=id,body,sender:person_detail!message_sender_fkey(name,sent),recipient:person_detail!message_recipient_fkey(name,received)&id=lt.4" `shouldRespondWith`
+            [json|
+              [{"id":1,"body":"Hello Jane","sender":{"name":"John","sent":2},"recipient":{"name":"Jane","received":2}},
+               {"id":2,"body":"Hi John","sender":{"name":"Jane","sent":1},"recipient":{"name":"John","received":1}},
+               {"id":3,"body":"How are you doing?","sender":{"name":"John","sent":2},"recipient":{"name":"Jane","received":2}}] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can specify a table!fk hint and request children 2 levels" $
+          get "/clients?id=eq.1&select=id,projects:projects!client(id,tasks(id))" `shouldRespondWith`
+            [json|[{"id":1,"projects":[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":3},{"id":4}]}]}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can disambiguate with the fk in case of an o2m and m2m relationship to the same table" $
+          get "/sites?select=name,main_project(name)&site_id=eq.1" `shouldRespondWith`
+            [json| [ { "name": "site 1", "main_project": { "name": "big project 1" } } ] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+      context "using the column name of the FK to specify the relationship" $ do
+        it "can embed by column" $
+          get "/projects?id=in.(1,3)&select=id,name,client_id(id,name)" `shouldRespondWith`
+            [json|[{"id":1,"name":"Windows 7","client_id":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":{"id":2,"name":"Apple"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can embed by column and select the column at the same time, if aliased" $
+          get "/projects?id=in.(1,3)&select=id,name,client_id,client:client_id(id,name)" `shouldRespondWith`
+            [json|[{"id":1,"name":"Windows 7","client_id":1,"client":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":2,"client":{"id":2,"name":"Apple"}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can embed parent by using view!column and grandparent by using the column" $
+          get "/tasks?id=eq.1&select=id,name,project:projects_view!project_id(id,name,client:client_id(id,name))" `shouldRespondWith`
+            [str|[{"id":1,"name":"Design w7","project":{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}}}]|]
+
+        it "can specify table!column" $
+          get "/message?select=id,body,sender:person!sender(name),recipient:person!recipient(name)&id=lt.4" `shouldRespondWith`
+            [json|
+              [{"id":1,"body":"Hello Jane","sender":{"name":"John"},"recipient":{"name":"Jane"}},
+               {"id":2,"body":"Hi John","sender":{"name":"Jane"},"recipient":{"name":"John"}},
+               {"id":3,"body":"How are you doing?","sender":{"name":"John"},"recipient":{"name":"Jane"}}] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "will embed using a column that has uppercase chars" $
+          get "/ghostBusters?select=escapeId(*)" `shouldRespondWith`
+            [json| [{"escapeId":{"so6meIdColumn":1}},{"escapeId":{"so6meIdColumn":3}},{"escapeId":{"so6meIdColumn":5}}] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds by using two columns pointing to the same table" $
+          get "/orders?id=eq.1&select=id, name, billing_address_id(id), shipping_address_id(id)" `shouldRespondWith`
+            [json|[{"id":1,"name":"order 1","billing_address_id":{"id":1},"shipping_address_id":{"id":2}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can disambiguate with the column in case of an o2m and m2m relationship to the same table" $
+          get "/sites?select=name,main_project_id(name)&site_id=eq.1" `shouldRespondWith`
+            [json| [ { "name": "site 1", "main_project_id": { "name": "big project 1" } } ] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+      context "using the junction to disambiguate the request" $
+        it "can specify the junction of an m2m relationship" $ do
+          get "/sites?select=*,big_projects!jobs(name)&site_id=in.(1,2)" `shouldRespondWith`
+            [json|
+              [
+                {
+                  "big_projects": [
+                    {
+                      "name": "big project 1"
+                    }
+                  ],
+                  "main_project_id": 1,
+                  "name": "site 1",
+                  "site_id": 1
+                },
+                {
+                  "big_projects": [
+                    {
+                      "name": "big project 1"
+                    },
+                    {
+                      "name": "big project 2"
+                    }
+                  ],
+                  "main_project_id": null,
+                  "name": "site 2",
+                  "site_id": 2
+                }
+              ]
+            |]
+          get "/sites?select=*,big_projects!main_jobs(name)&site_id=in.(1,2)" `shouldRespondWith`
+            [json|
+              [
+                {
+                  "big_projects": [
+                    {
+                      "name": "big project 1"
+                    }
+                  ],
+                  "main_project_id": 1,
+                  "name": "site 1",
+                  "site_id": 1
+                },
+                {
+                  "big_projects": [],
+                  "main_project_id": null,
+                  "name": "site 2",
+                  "site_id": 2
+                }
+              ]
+            |]
+            { matchHeaders = [matchContentTypeJson] }
+
+      context "using a FK column and a FK to specify the relationship" $
+        it "embeds by using a column and a fk pointing to the same table" $
+          get "/orders?id=eq.1&select=id, name, billing_address_id(id), shipping(id)" `shouldRespondWith`
+            [json|[{"id":1,"name":"order 1","billing_address_id":{"id":1},"shipping":{"id":2}}]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+    context "tables with self reference foreign keys" $ do
+      context "one self reference foreign key" $ do
+        it "embeds parents recursively" $
+          get "/family_tree?id=in.(3,4)&select=id,parent(id,name,parent(*))" `shouldRespondWith`
+            [json|[
+              { "id": "3", "parent": { "id": "1", "name": "Parental Unit", "parent": null } },
+              { "id": "4", "parent": { "id": "2", "name": "Kid One", "parent": { "id": "1", "name": "Parental Unit", "parent": null } } }
+            ]|]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds children recursively" $
+          get "/family_tree?id=eq.1&select=id,name, children:family_tree!parent(id,name,children:family_tree!parent(id,name))" `shouldRespondWith`
+            [json|[{
+              "id": "1", "name": "Parental Unit", "children": [
+                { "id": "2", "name": "Kid One", "children": [ { "id": "4", "name": "Grandkid One" } ] },
+                { "id": "3", "name": "Kid Two", "children": [ { "id": "5", "name": "Grandkid Two" } ] }
+              ]
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds parent and then embeds children" $
+          get "/family_tree?id=eq.2&select=id,name,parent(id,name,children:family_tree!parent(id,name))" `shouldRespondWith`
+            [json|[{
+              "id": "2", "name": "Kid One", "parent": {
+                "id": "1", "name": "Parental Unit", "children": [ { "id": "2", "name": "Kid One" }, { "id": "3", "name": "Kid Two"} ]
+              }
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+      context "two self reference foreign keys" $ do
+        it "embeds parents" $
+          get "/organizations?select=id,name,referee(id,name),auditor(id,name)&id=eq.3" `shouldRespondWith`
+            [json|[{
+              "id": 3, "name": "Acme",
+              "referee": {
+                "id": 1,
+                "name": "Referee Org"
+              },
+              "auditor": {
+                "id": 2,
+                "name": "Auditor Org"
+              }
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds children" $ do
+          get "/organizations?select=id,name,refereeds:organizations!referee(id,name)&id=eq.1" `shouldRespondWith`
+            [json|[{
+              "id": 1, "name": "Referee Org",
+              "refereeds": [
+                {
+                  "id": 3,
+                  "name": "Acme"
+                },
+                {
+                  "id": 4,
+                  "name": "Umbrella"
+                }
+              ]
+            }]|] { matchHeaders = [matchContentTypeJson] }
+          get "/organizations?select=id,name,auditees:organizations!auditor(id,name)&id=eq.2" `shouldRespondWith`
+            [json|[{
+              "id": 2, "name": "Auditor Org",
+              "auditees": [
+                {
+                  "id": 3,
+                  "name": "Acme"
+                },
+                {
+                  "id": 4,
+                  "name": "Umbrella"
+                }
+              ]
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+        it "embeds other relations(manager) besides the self reference" $ do
+          get "/organizations?select=name,manager(name),referee(name,manager(name),auditor(name,manager(name))),auditor(name,manager(name),referee(name,manager(name)))&id=eq.5" `shouldRespondWith`
+            [json|[{
+              "name":"Cyberdyne",
+              "manager":{"name":"Cyberdyne Manager"},
+              "referee":{
+                "name":"Acme",
+                "manager":{"name":"Acme Manager"},
+                "auditor":{
+                  "name":"Auditor Org",
+                  "manager":{"name":"Auditor Manager"}}},
+              "auditor":{
+                "name":"Umbrella",
+                "manager":{"name":"Umbrella Manager"},
+                "referee":{
+                  "name":"Referee Org",
+                  "manager":{"name":"Referee Manager"}}}
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+          get "/organizations?select=name,manager(name),auditees:organizations!auditor(name,manager(name),refereeds:organizations!referee(name,manager(name)))&id=eq.2" `shouldRespondWith`
+            [json|[{
+              "name":"Auditor Org",
+              "manager":{"name":"Auditor Manager"},
+              "auditees":[
+                {"name":"Acme",
+                 "manager":{"name":"Acme Manager"},
+                 "refereeds":[
+                   {"name":"Cyberdyne",
+                    "manager":{"name":"Cyberdyne Manager"}},
+                   {"name":"Oscorp",
+                    "manager":{"name":"Oscorp Manager"}}]},
+                {"name":"Umbrella",
+                 "manager":{"name":"Umbrella Manager"},
+                 "refereeds":[]}]
+            }]|] { matchHeaders = [matchContentTypeJson] }
+
+    -- TODO Remove in next major version
+    describe "old dot '.' symbol, deprecated" $
+      it "still works" $ do
+        get "/clients?id=eq.1&select=id,projects:projects.client_id(id,tasks(id))" `shouldRespondWith`
+          [json|[{"id":1,"projects":[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":3},{"id":4}]}]}]|]
+          { matchHeaders = [matchContentTypeJson] }
+        get "/tasks?select=id,users:users.users_tasks(id)" `shouldRespondWith`
+          [json|[{"id":1,"users":[{"id":1},{"id":3}]},{"id":2,"users":[{"id":1}]},{"id":3,"users":[{"id":1}]},{"id":4,"users":[{"id":1}]},{"id":5,"users":[{"id":2},{"id":3}]},{"id":6,"users":[{"id":2}]},{"id":7,"users":[{"id":2}]},{"id":8,"users":[]}]|]
+          { matchHeaders = [matchContentTypeJson] }
+
@@ -9,7 +9,7 @@ import Test.Hspec.Wai.JSON
 import Protolude
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "extra search path" $ do

  it "finds the ltree <@ operator on the public schema" $
@@ -0,0 +1,30 @@
+module Feature.HtmlRawOutputSpec where
+
+import Network.Wai (Application)
+
+import Network.HTTP.Types
+import Test.Hspec         hiding (pendingWith)
+import Test.Hspec.Wai
+import Text.Heredoc
+
+import Protolude  hiding (get)
+import SpecHelper (acceptHdrs)
+
+spec :: SpecWith ((), Application)
+spec = describe "When raw-media-types is set to \"text/html\"" $
+  it "can get raw output with Accept: text/html" $
+    request methodGet "/rpc/welcome.html" (acceptHdrs "text/html") ""
+      `shouldRespondWith`
+      [str|
+          |<html>
+          |  <head>
+          |    <title>PostgREST</title>
+          |  </head>
+          |  <body>
+          |    <h1>Welcome to PostgREST</h1>
+          |  </body>
+          |</html>
+          |]
+      { matchStatus = 200
+      , matchHeaders = ["Content-Type" <:> "text/html; charset=utf-8"]
+      }
@@ -2,7 +2,6 @@ module Feature.InsertSpec where

 import qualified Data.Aeson as JSON

-import Control.Monad          (replicateM_, void)
 import Data.List              (lookup)
 import Data.Maybe             (fromJust)
 import Network.Wai            (Application)
@@ -20,7 +19,7 @@ import PostgREST.Types (PgVersion, pgVersion112)
 import Protolude       hiding (get)
 import SpecHelper

-spec :: PgVersion -> SpecWith Application
+spec :: PgVersion -> SpecWith ((), Application)
 spec actualPgVersion = do
  describe "Posting new record" $ do
    context "disparate json types" $ do
@@ -48,6 +47,22 @@ spec actualPgVersion = do
          , matchHeaders = [matchContentTypeJson]
          }

+      it "ignores &select when return not set or using return=minimal" $ do
+        request methodPost "/menagerie?select=integer,varchar" []
+          [json| [{
+            "integer": 15, "double": 3.14159, "varchar": "testing!"
+          , "boolean": false, "date": "1900-01-01", "money": "$3.99"
+          , "enum": "foo"
+          }] |] `shouldRespondWith` ""
+          { matchStatus  = 201 }
+        request methodPost "/menagerie?select=integer,varchar" [("Prefer", "return=minimal")]
+          [json| [{
+            "integer": 16, "double": 3.14159, "varchar": "testing!"
+          , "boolean": false, "date": "1900-01-01", "money": "$3.99"
+          , "enum": "foo"
+          }] |] `shouldRespondWith` ""
+          { matchStatus  = 201 }
+
    context "non uniform json array" $ do
      it "rejects json array that isn't exclusivily composed of objects" $
        post "/articles"
@@ -148,15 +163,6 @@ spec actualPgVersion = do
            simpleBody p `shouldBe` [json| [] |]
            simpleStatus p `shouldBe` created201

-        it "can insert in tables with no select privileges" $ do
-          p <- request methodPost "/insertonly"
-                       [("Prefer", "return=minimal")]
-                       [json| { "v":"some value" } |]
-          liftIO $ do
-            simpleBody p `shouldBe` ""
-            simpleStatus p `shouldBe` created201
-
-
        it "can post nulls" $ do
          p <- request methodPost "/no_pk"
                       [("Prefer", "return=representation")]
@@ -198,7 +204,16 @@ spec actualPgVersion = do
      it "fails with 400 and error" $
        post "/simple_pk" "}{ x = 2"
        `shouldRespondWith`
-        [json|{"message":"Error in $: Failed reading: not a valid json value"}|]
+        [json|{"message":"Error in $: Failed reading: not a valid json value at '}{x=2'"}|]
+        { matchStatus  = 400
+        , matchHeaders = [matchContentTypeJson]
+        }
+
+    context "with no payload" $
+      it "fails with 400 and error" $
+        post "/simple_pk" ""
+        `shouldRespondWith`
+        [json|{"message":"Error in $: not enough input"}|]
        { matchStatus  = 400
        , matchHeaders = [matchContentTypeJson]
        }
@@ -260,34 +275,18 @@ spec actualPgVersion = do
          , matchHeaders = []
          }

-    context "table with limited privileges" $ do
-      it "succeeds if correct select is applied" $
-        request methodPost "/limited_article_stars?select=article_id,user_id" [("Prefer", "return=representation")]
-          [json| {"article_id": 2, "user_id": 1} |] `shouldRespondWith` [str|[{"article_id":2,"user_id":1}]|]
-          { matchStatus  = 201
-          , matchHeaders = []
+      it "successfully inserts a row with all-default columns with prefer=rep" $
+        request methodPost "/items" [("Prefer", "return=representation")] "{}"
+          `shouldRespondWith` [json|[{ id: 20 }]|]
+          { matchStatus  = 201,
+            matchHeaders = []
          }
-      it "fails if more columns are selected" $
-        request methodPost "/limited_article_stars?select=article_id,user_id,created_at" [("Prefer", "return=representation")]
-          [json| {"article_id": 2, "user_id": 2} |] `shouldRespondWith` (
-        if actualPgVersion >= pgVersion112 then
-        [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for view limited_article_stars"}|]
-           else
-        [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for relation limited_article_stars"}|]
-                                                                        )
-          { matchStatus  = 401
-          , matchHeaders = []
-          }
-      it "fails if select is not specified" $
-        request methodPost "/limited_article_stars" [("Prefer", "return=representation")]
-          [json| {"article_id": 3, "user_id": 1} |] `shouldRespondWith` (
-        if actualPgVersion >= pgVersion112 then
-        [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for view limited_article_stars"}|]
-           else
-        [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for relation limited_article_stars"}|]
-                                                                        )
-          { matchStatus  = 401
-          , matchHeaders = []
+
+      it "successfully inserts a row with all-default columns with prefer=rep and &select=" $
+        request methodPost "/items?select=id" [("Prefer", "return=representation")] "{}"
+          `shouldRespondWith` [json|[{ id: 21 }]|]
+          { matchStatus  = 201,
+            matchHeaders = []
          }

    context "POST with ?columns parameter" $ do
@@ -422,6 +421,24 @@ spec actualPgVersion = do
            matchHeaders = []
          }

+    context "with invalid json payload" $
+      it "fails with 400 and error" $
+        request methodPatch "/simple_pk" [] "}{ x = 2"
+          `shouldRespondWith`
+          [json|{"message":"Error in $: Failed reading: not a valid json value at '}{x=2'"}|]
+          { matchStatus  = 400,
+            matchHeaders = [matchContentTypeJson]
+          }
+
+    context "with no payload" $
+      it "fails with 400 and error" $
+        request methodPatch "/items" [] ""
+          `shouldRespondWith`
+          [json|{"message":"Error in $: not enough input"}|]
+          { matchStatus  = 400,
+            matchHeaders = [matchContentTypeJson]
+          }
+
    context "in a nonempty table" $ do
      it "can update a single item" $ do
        g <- get "/items?id=eq.42"
@@ -503,47 +520,123 @@ spec actualPgVersion = do
              matchHeaders = []
            }

-      it "can provide a representation" $ do
-        _ <- post "/items"
-          [json| { id: 1 } |]
-        request methodPatch
-          "/items?id=eq.1"
-          [("Prefer", "return=representation")]
-          [json| { id: 99 } |]
-          `shouldRespondWith` [json| [{id:99}] |]
-          { matchHeaders = [matchContentTypeJson] }
-        -- put value back for other tests
-        void $ request methodPatch "/items?id=eq.99" [] [json| { "id":1 } |]
+      context "with representation requested" $ do
+        it "can provide a representation" $ do
+          _ <- post "/items"
+            [json| { id: 1 } |]
+          request methodPatch
+            "/items?id=eq.1"
+            [("Prefer", "return=representation")]
+            [json| { id: 99 } |]
+            `shouldRespondWith` [json| [{id:99}] |]
+            { matchHeaders = [matchContentTypeJson] }
+          -- put value back for other tests
+          void $ request methodPatch "/items?id=eq.99" [] [json| { "id":1 } |]

-      it "makes no updates and returns 204, when patching with an empty json object/array" $ do
-        request methodPatch "/items" [] [json| {} |]
+        it "can return computed columns" $
+          request methodPatch
+            "/items?id=eq.1&select=id,always_true"
+            [("Prefer", "return=representation")]
+            [json| { id: 1 } |]
+            `shouldRespondWith` [json| [{ id: 1, always_true: true }] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+        it "can select overloaded computed columns" $ do
+          request methodPatch
+            "/items?id=eq.1&select=id,computed_overload"
+            [("Prefer", "return=representation")]
+            [json| { id: 1 } |]
+            `shouldRespondWith` [json| [{ id: 1, computed_overload: true }] |]
+            { matchHeaders = [matchContentTypeJson] }
+          request methodPatch
+            "/items2?id=eq.1&select=id,computed_overload"
+            [("Prefer", "return=representation")]
+            [json| { id: 1 } |]
+            `shouldRespondWith` [json| [{ id: 1, computed_overload: true }] |]
+            { matchHeaders = [matchContentTypeJson] }
+
+      it "ignores ?select= when return not set or return=minimal" $ do
+        request methodPatch "/items?id=eq.1&select=id" [] [json| { id:1 } |]
          `shouldRespondWith` ""
          {
            matchStatus  = 204,
-            matchHeaders = ["Content-Range" <:> "*/*"]
+            matchHeaders = ["Content-Range" <:> "0-0/*"]
          }
-
-        request methodPatch "/items" [] [json| [] |]
+        request methodPatch "/items?id=eq.1&select=id" [("Prefer", "return=minimal")] [json| { id:1 } |]
          `shouldRespondWith` ""
          {
            matchStatus  = 204,
-            matchHeaders = ["Content-Range" <:> "*/*"]
+            matchHeaders = ["Content-Range" <:> "0-0/*"]
          }

-        request methodPatch "/items" [] [json| [{}] |]
-          `shouldRespondWith` ""
-          {
-            matchStatus  = 204,
-            matchHeaders = ["Content-Range" <:> "*/*"]
-          }
+      context "when patching with an empty body" $ do
+        it "makes no updates and returns 204 without return= and without ?select=" $ do
+          request methodPatch "/items" [] [json| {} |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }

-      it "makes no updates and and returns 200, when patching with an empty json object and return=rep" $
-        request methodPatch "/items" [("Prefer", "return=representation")] [json| {} |]
-          `shouldRespondWith` "[]"
-          {
-            matchStatus  = 200,
-            matchHeaders = ["Content-Range" <:> "*/*"]
-          }
+          request methodPatch "/items" [] [json| [] |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+          request methodPatch "/items" [] [json| [{}] |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+        it "makes no updates and returns 204 without return= and with ?select=" $ do
+          request methodPatch "/items?select=id" [] [json| {} |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+          request methodPatch "/items?select=id" [] [json| [] |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+          request methodPatch "/items?select=id" [] [json| [{}] |]
+            `shouldRespondWith` ""
+            {
+              matchStatus  = 204,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+        it "makes no updates and returns 200 with return=rep and without ?select=" $
+          request methodPatch "/items" [("Prefer", "return=representation")] [json| {} |]
+            `shouldRespondWith` "[]"
+            {
+              matchStatus  = 200,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+        it "makes no updates and returns 200 with return=rep and with ?select=" $
+          request methodPatch "/items?select=id" [("Prefer", "return=representation")] [json| {} |]
+            `shouldRespondWith` "[]"
+            {
+              matchStatus  = 200,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }
+
+        it "makes no updates and returns 200 with return=rep and with ?select= for overloaded computed columns" $
+          request methodPatch "/items?select=id,computed_overload" [("Prefer", "return=representation")] [json| {} |]
+            `shouldRespondWith` "[]"
+            {
+              matchStatus  = 200,
+              matchHeaders = ["Content-Range" <:> "*/*"]
+            }

    context "with unicode values" $
      it "succeeds and returns values intact" $ do
@@ -588,3 +681,129 @@ spec actualPgVersion = do
      liftIO $ do
        simpleBody p2 `shouldBe` [str|[{"owner":"jroe","secret":"lolcat"}]|]
        simpleStatus p2 `shouldBe` created201
+
+  context "tables with self reference foreign keys" $ do
+    it "embeds parent after insert" $
+      request methodPost "/web_content?select=id,name,parent_content:p_web_id(name)"
+              [("Prefer", "return=representation")]
+        [json|{"id":6, "name":"wot", "p_web_id":4}|]
+        `shouldRespondWith`
+        [json|[{"id":6,"name":"wot","parent_content":{"name":"wut"}}]|]
+        { matchStatus  = 201
+        , matchHeaders = [ matchContentTypeJson , "Location" <:> "/web_content?id=eq.6" ]
+        }
+
+    it "embeds children after update" $
+      request methodPatch "/web_content?id=eq.0&select=id,name,web_content(name)"
+              [("Prefer", "return=representation")]
+        [json|{"name": "tardis-patched"}|]
+        `shouldRespondWith`
+        [json|
+          [ { "id": 0, "name": "tardis-patched", "web_content": [ { "name": "fezz" }, { "name": "foo" }, { "name": "bar" } ]} ]
+        |]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+
+    it "embeds parent, children and grandchildren after update" $
+      request methodPatch "/web_content?id=eq.0&select=id,name,web_content(name,web_content(name)),parent_content:p_web_id(name)"
+              [("Prefer", "return=representation")]
+        [json|{"name": "tardis-patched-2"}|]
+        `shouldRespondWith`
+        [json| [
+          {
+            "id": 0,
+            "name": "tardis-patched-2",
+            "parent_content": { "name": "wat" },
+            "web_content": [
+                { "name": "fezz", "web_content": [ { "name": "wut" } ] },
+                { "name": "foo",  "web_content": [] },
+                { "name": "bar",  "web_content": [] }
+            ]
+          }
+        ] |]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+
+    it "embeds children after update without explicitly including the id in the ?select" $
+      request methodPatch "/web_content?id=eq.0&select=name,web_content(name)"
+              [("Prefer", "return=representation")]
+        [json|{"name": "tardis-patched"}|]
+        `shouldRespondWith`
+        [json|
+          [ { "name": "tardis-patched", "web_content": [ { "name": "fezz" }, { "name": "foo" }, { "name": "bar" } ]} ]
+        |]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+
+    it "embeds an M2M relationship plus parent after update" $
+      request methodPatch "/users?id=eq.1&select=name,tasks(name,project:projects(name))"
+              [("Prefer", "return=representation")]
+        [json|{"name": "Kevin Malone"}|]
+        `shouldRespondWith`
+        [json|[
+          {
+            "name": "Kevin Malone",
+            "tasks": [
+                { "name": "Design w7", "project": { "name": "Windows 7" } },
+                { "name": "Code w7", "project": { "name": "Windows 7" } },
+                { "name": "Design w10", "project": { "name": "Windows 10" } },
+                { "name": "Code w10", "project": { "name": "Windows 10" } }
+            ]
+          }
+        ]|]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+
+  context "table with limited privileges" $ do
+    it "succeeds inserting if correct select is applied" $
+      request methodPost "/limited_article_stars?select=article_id,user_id" [("Prefer", "return=representation")]
+        [json| {"article_id": 2, "user_id": 1} |] `shouldRespondWith` [str|[{"article_id":2,"user_id":1}]|]
+        { matchStatus  = 201
+        , matchHeaders = []
+        }
+
+    it "fails inserting if more columns are selected" $
+      request methodPost "/limited_article_stars?select=article_id,user_id,created_at" [("Prefer", "return=representation")]
+        [json| {"article_id": 2, "user_id": 2} |] `shouldRespondWith` (
+      if actualPgVersion >= pgVersion112 then
+      [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for view limited_article_stars"}|]
+         else
+      [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for relation limited_article_stars"}|]
+                                                                      )
+        { matchStatus  = 401
+        , matchHeaders = []
+        }
+
+    it "fails inserting if select is not specified" $
+      request methodPost "/limited_article_stars" [("Prefer", "return=representation")]
+        [json| {"article_id": 3, "user_id": 1} |] `shouldRespondWith` (
+      if actualPgVersion >= pgVersion112 then
+      [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for view limited_article_stars"}|]
+         else
+      [str|{"hint":null,"details":null,"code":"42501","message":"permission denied for relation limited_article_stars"}|]
+                                                                      )
+        { matchStatus  = 401
+        , matchHeaders = []
+        }
+
+    it "can insert in a table with no select and return=minimal" $ do
+      p <- request methodPost "/insertonly"
+                   [("Prefer", "return=minimal")]
+                   [json| { "v":"some value" } |]
+      liftIO $ do
+        simpleBody p `shouldBe` ""
+        simpleStatus p `shouldBe` created201
+
+    it "succeeds updating row and gives a 204 when using return=minimal" $
+      request methodPatch "/app_users?id=eq.1" [("Prefer", "return=minimal")]
+        [json| { "password": "passxyz" } |]
+          `shouldRespondWith` 204
+
+    it "can update without return=minimal and no explicit select" $
+      request methodPatch "/app_users?id=eq.1" []
+        [json| { "password": "passabc" } |]
+          `shouldRespondWith` 204
@@ -7,11 +7,11 @@ import Test.Hspec
 import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON

-import PostgREST.Types (PgVersion, pgVersion112)
+import PostgREST.Types (PgVersion, pgVersion112, pgVersion121)
 import Protolude       hiding (get)
 import SpecHelper

-spec :: PgVersion -> SpecWith Application
+spec :: PgVersion -> SpecWith ((), Application)
 spec actualPgVersion = describe "json and jsonb operators" $ do
  context "Shaping response with select parameter" $ do
    it "obtains a json subfield one level with casting" $
@@ -26,7 +26,12 @@ spec actualPgVersion = describe "json and jsonb operators" $ do

    it "fails on bad casting (data of the wrong format)" $
      get "/complex_items?select=settings->foo->>bar::integer"
-        `shouldRespondWith` [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
+        `shouldRespondWith` (
+        if actualPgVersion >= pgVersion121 then
+        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for type integer: \"baz\""} |]
+        else
+        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
+                            )
        { matchStatus  = 400 , matchHeaders = [] }

    it "obtains a json subfield two levels (string)" $
@@ -0,0 +1,336 @@
+module Feature.MultipleSchemaSpec where
+
+import Control.Lens    ((^?))
+import Data.Aeson.Lens
+import Data.Aeson.QQ
+
+import Network.HTTP.Types
+import Network.Wai        (Application)
+import Network.Wai.Test   (SResponse (simpleHeaders), simpleBody)
+
+import Test.Hspec
+import Test.Hspec.Wai
+import Test.Hspec.Wai.JSON
+
+import Protolude
+import SpecHelper
+
+import PostgREST.Types (PgVersion, pgVersion96)
+
+spec :: PgVersion -> SpecWith ((), Application)
+spec actualPgVersion =
+  describe "multiple schemas in single instance" $ do
+    context "Reading tables on different schemas" $ do
+      it "succeeds in reading table from default schema v1 if no schema is selected via header" $
+        request methodGet "/parents" [] "" `shouldRespondWith`
+          [json|[
+            {"id":1,"name":"parent v1-1"},
+            {"id":2,"name":"parent v1-2"}
+          ]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds in reading table from default schema v1 after explicitly passing it in the header" $
+        request methodGet "/parents" [("Accept-Profile", "v1")] "" `shouldRespondWith`
+          [json|[
+            {"id":1,"name":"parent v1-1"},
+            {"id":2,"name":"parent v1-2"}
+          ]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds in reading table from schema v2" $
+        request methodGet "/parents" [("Accept-Profile", "v2")] "" `shouldRespondWith`
+          [json|[
+            {"id":3,"name":"parent v2-3"},
+            {"id":4,"name":"parent v2-4"}
+          ]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      it "succeeds in reading another_table from schema v2" $
+        request methodGet "/another_table" [("Accept-Profile", "v2")] "" `shouldRespondWith`
+          [json|[
+            {"id":5,"another_value":"value 5"},
+            {"id":6,"another_value":"value 6"}
+          ]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      it "doesn't find another_table in schema v1" $
+        request methodGet "/another_table" [("Accept-Profile", "v1")] "" `shouldRespondWith` 404
+
+      it "fails trying to read table from unkown schema" $
+        request methodGet "/parents" [("Accept-Profile", "unkown")] "" `shouldRespondWith`
+          [json|{"message":"The schema must be one of the following: v1, v2"}|]
+          {
+            matchStatus = 406
+          }
+
+    context "Inserting tables on different schemas" $ do
+      it "succeeds inserting on default schema and returning it" $
+        request methodPost "/children" [("Prefer", "return=representation")] [json|{"name": "child v1-1", "parent_id": 1}|]
+         `shouldRespondWith`
+         [json|[{"id":1, "name": "child v1-1", "parent_id": 1}]|]
+         {
+           matchStatus = 201
+         , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+         }
+
+      it "succeeds inserting on the v1 schema and returning its parent" $
+        request methodPost "/children?select=id,parent(*)" [("Prefer", "return=representation"), ("Content-Profile", "v1")]
+          [json|{"name": "child v1-2", "parent_id": 2}|]
+          `shouldRespondWith`
+          [json|[{"id":2, "parent": {"id": 2, "name": "parent v1-2"}}]|]
+          {
+            matchStatus = 201
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds inserting on the v2 schema and returning its parent" $
+        request methodPost "/children?select=id,parent(*)" [("Prefer", "return=representation"), ("Content-Profile", "v2")]
+          [json|{"name": "child v2-3", "parent_id": 3}|]
+          `shouldRespondWith`
+          [json|[{"id":1, "parent": {"id": 3, "name": "parent v2-3"}}]|]
+          {
+            matchStatus = 201
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      it "fails when inserting on an unknown schema" $
+        request methodPost "/children" [("Content-Profile", "unknown")]
+          [json|{"name": "child 4", "parent_id": 4}|]
+          `shouldRespondWith`
+          [json|{"message":"The schema must be one of the following: v1, v2"}|]
+          {
+            matchStatus = 406
+          }
+
+    context "calling procs on different schemas" $ do
+      it "succeeds in calling the default schema proc" $
+        request methodGet "/rpc/get_parents_below?id=6" [] ""
+          `shouldRespondWith`
+          [json|[{"id":1,"name":"parent v1-1"}, {"id":2,"name":"parent v1-2"}]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds in calling the v1 schema proc and embedding" $
+        request methodGet "/rpc/get_parents_below?id=6&select=id,name,children(id,name)" [("Accept-Profile", "v1")] ""
+          `shouldRespondWith`
+          [json| [
+            {"id":1,"name":"parent v1-1","children":[{"id":1,"name":"child v1-1"}]},
+            {"id":2,"name":"parent v1-2","children":[{"id":2,"name":"child v1-2"}]}] |]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds in calling the v2 schema proc and embedding" $
+        request methodGet "/rpc/get_parents_below?id=6&select=id,name,children(id,name)" [("Accept-Profile", "v2")] ""
+          `shouldRespondWith`
+          [json| [
+            {"id":3,"name":"parent v2-3","children":[{"id":1,"name":"child v2-3"}]},
+            {"id":4,"name":"parent v2-4","children":[]}] |]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      it "succeeds in calling the v2 schema proc with POST by using Content-Profile" $
+        request methodPost "/rpc/get_parents_below?select=id,name" [("Content-Profile", "v2")]
+          [json|{"id": "6"}|]
+          `shouldRespondWith`
+          [json| [
+            {"id":3,"name":"parent v2-3"},
+            {"id":4,"name":"parent v2-4"}]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+    context "Modifying tables on different schemas" $ do
+      it "succeeds in patching on the v1 schema and returning its parent" $
+        request methodPatch "/children?select=name,parent(name)&id=eq.1" [("Content-Profile", "v1"), ("Prefer", "return=representation")]
+          [json|{"name": "child v1-1 updated"}|]
+          `shouldRespondWith`
+          [json|[{"name":"child v1-1 updated", "parent": {"name": "parent v1-1"}}]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v1"]
+          }
+
+      it "succeeds in patching on the v2 schema and returning its parent" $
+        request methodPatch "/children?select=name,parent(name)&id=eq.1" [("Content-Profile", "v2"), ("Prefer", "return=representation")]
+          [json|{"name": "child v2-1 updated"}|]
+          `shouldRespondWith`
+          [json|[{"name":"child v2-1 updated", "parent": {"name": "parent v2-3"}}]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      it "succeeds on deleting on the v2 schema" $ do
+        request methodDelete "/children?id=eq.1" [("Content-Profile", "v2"), ("Prefer", "return=representation")] ""
+          `shouldRespondWith` [json|[{"id": 1, "name": "child v2-1 updated", "parent_id": 3}]|]
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+        request methodGet "/children?id=eq.1" [("Accept-Profile", "v2")] ""
+          `shouldRespondWith` "[]"
+          {
+            matchStatus = 200
+          , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+          }
+
+      when (actualPgVersion >= pgVersion96) $
+        it "succeeds on PUT on the v2 schema" $
+          request methodPut "/children?id=eq.111" [("Content-Profile", "v2"), ("Prefer", "return=representation")]
+            [json| [ { "id": 111, "name": "child v2-111", "parent_id": null } ]|]
+            `shouldRespondWith`
+            [json|[{ "id": 111, "name": "child v2-111", "parent_id": null }]|]
+            {
+              matchStatus = 200
+            , matchHeaders = [matchContentTypeJson, "Content-Profile" <:> "v2"]
+            }
+
+    context "OpenAPI output" $ do
+      it "succeeds in reading table definition from default schema v1 if no schema is selected via header" $ do
+          req <- request methodGet "/" [] ""
+
+          liftIO $ do
+            simpleHeaders req `shouldSatisfy` matchHeader "Content-Profile" "v1"
+
+            let def = simpleBody req ^? key "definitions" . key "parents"
+
+            def `shouldBe` Just
+                [aesonQQ|
+                  {
+                    "type" : "object",
+                    "properties" : {
+                      "id" : {
+                        "description" : "Note:\nThis is a Primary Key.<pk/>",
+                        "format" : "integer",
+                        "type" : "integer"
+                      },
+                      "name" : {
+                        "format" : "text",
+                        "type" : "string"
+                      }
+                    },
+                    "required" : [
+                      "id"
+                    ]
+                  }
+                |]
+
+      it "succeeds in reading table definition from default schema v1 after explicitly passing it in the header" $ do
+          r <- request methodGet "/" [("Accept-Profile", "v1")] ""
+
+          liftIO $ do
+            simpleHeaders r `shouldSatisfy` matchHeader "Content-Profile" "v1"
+
+            let def = simpleBody r ^? key "definitions" . key "parents"
+
+            def `shouldBe` Just
+                [aesonQQ|
+                  {
+                    "type" : "object",
+                    "properties" : {
+                      "id" : {
+                        "description" : "Note:\nThis is a Primary Key.<pk/>",
+                        "format" : "integer",
+                        "type" : "integer"
+                      },
+                      "name" : {
+                        "format" : "text",
+                        "type" : "string"
+                      }
+                    },
+                    "required" : [
+                      "id"
+                    ]
+                  }
+                |]
+
+      it "succeeds in reading table definition from schema v2" $ do
+          r <- request methodGet "/" [("Accept-Profile", "v2")] ""
+
+          liftIO $ do
+            simpleHeaders r `shouldSatisfy` matchHeader "Content-Profile" "v2"
+
+            let def = simpleBody r ^? key "definitions" . key "parents"
+
+            def `shouldBe` Just
+                [aesonQQ|
+                  {
+                    "type" : "object",
+                    "properties" : {
+                      "id" : {
+                        "description" : "Note:\nThis is a Primary Key.<pk/>",
+                        "format" : "integer",
+                        "type" : "integer"
+                      },
+                      "name" : {
+                        "format" : "text",
+                        "type" : "string"
+                      }
+                    },
+                    "required" : [
+                      "id"
+                    ]
+                  }
+                |]
+
+      it "succeeds in reading another_table definition from schema v2" $ do
+          r <- request methodGet "/" [("Accept-Profile", "v2")] ""
+
+          liftIO $ do
+            simpleHeaders r `shouldSatisfy` matchHeader "Content-Profile" "v2"
+
+            let def = simpleBody r ^? key "definitions" . key "another_table"
+
+            def `shouldBe` Just
+                [aesonQQ|
+                  {
+                    "type" : "object",
+                    "properties" : {
+                      "id" : {
+                        "description" : "Note:\nThis is a Primary Key.<pk/>",
+                        "format" : "integer",
+                        "type" : "integer"
+                      },
+                      "another_value" : {
+                        "format" : "text",
+                        "type" : "string"
+                      }
+                    },
+                    "required" : [
+                      "id"
+                    ]
+                  }
+                |]
+
+      it "doesn't find another_table definition in schema v1" $ do
+        r <- request methodGet "/" [("Accept-Profile", "v1")] ""
+
+        liftIO $ do
+          let def = simpleBody r ^? key "definitions" . key "another_table"
+          def `shouldBe` Nothing
+
+      it "fails trying to read definitions from unkown schema" $
+        request methodGet "/" [("Accept-Profile", "unkown")] "" `shouldRespondWith`
+          [json|{"message":"The schema must be one of the following: v1, v2"}|]
+          {
+            matchStatus = 406
+          }
@@ -13,7 +13,7 @@ import Protolude
 import SpecHelper
 -- }}}

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "server started without JWT secret" $ do

  -- this test will stop working 9999999999s after the UNIX EPOCH
@@ -7,7 +7,7 @@ import Test.Hspec.Wai

 import Protolude hiding (get)

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "Non existent api schema" $ do
    it "succeeds when requesting root path" $
@@ -9,7 +9,7 @@ import Test.Hspec.Wai.JSON
 import Protolude  hiding (get)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = describe "features supported on PostgreSQL 9.5" $
  context "json array negative index" $ do
    it "can select with negative indexes" $ do
@@ -1,6 +1,8 @@
 module Feature.PgVersion96Spec where

-import Network.Wai (Application)
+import Network.HTTP.Types
+import Network.Wai        (Application)
+import Network.Wai.Test   (SResponse (simpleHeaders))

 import Test.Hspec
 import Test.Hspec.Wai
@@ -9,10 +11,10 @@ import Test.Hspec.Wai.JSON
 import Protolude  hiding (get)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "features supported on PostgreSQL 9.6" $ do
-    context "GUC headers" $ do
+    context "GUC headers on function calls" $ do
      it "succeeds setting the headers" $ do
        get "/rpc/get_projects_and_guc_headers?id=eq.2&select=id"
          `shouldRespondWith` [json|[{"id": 2}]|]
@@ -67,6 +69,98 @@ spec =
              "Set-Cookie" <:> "sessionid=38afes7a8; HttpOnly; Path=/",
              "Set-Cookie" <:> "id=a3fWa; Expires=Wed, 21 Oct 2015 07:28:00 GMT; Secure; HttpOnly"]}

+    context "GUC headers on all other methods via pre-request" $ do
+      it "succeeds setting the headers on GET and HEAD" $ do
+        request methodGet "/items?id=eq.1" [("User-Agent", "MSIE 6.0")] mempty
+          `shouldRespondWith` [json|[{"id": 1}]|]
+          {matchHeaders = [
+              matchContentTypeJson,
+              "Cache-Control" <:> "no-cache, no-store, must-revalidate"]}
+
+        request methodHead "/items?id=eq.1" [("User-Agent", "MSIE 7.0")] mempty
+          `shouldRespondWith` ""
+          {matchHeaders = ["Cache-Control" <:> "no-cache, no-store, must-revalidate"]}
+
+        request methodHead "/projects" [("Accept", "text/csv")] mempty
+          `shouldRespondWith` ""
+          {matchHeaders = ["Content-Disposition" <:> "attachment; filename=projects.csv"]}
+
+      it "succeeds setting the headers on POST" $
+        request methodPost "/items" [] [json|[{"id": 11111}]|]
+          `shouldRespondWith` ""
+          { matchStatus = 201
+          , matchHeaders = ["X-Custom-Header" <:> "mykey=myval"]
+          }
+
+      it "succeeds setting the headers on PATCH" $
+        request methodPatch "/items?id=eq.11111" [] [json|[{"id": 11111}]|]
+          `shouldRespondWith` ""
+          { matchStatus = 204
+          , matchHeaders = ["X-Custom-Header" <:> "mykey=myval"]
+          }
+
+      it "succeeds setting the headers on PUT" $
+        request methodPut "/items?id=eq.11111" [] [json|[{"id": 11111}]|]
+          `shouldRespondWith` ""
+          { matchStatus = 204
+          , matchHeaders = ["X-Custom-Header" <:> "mykey=myval"]
+          }
+
+      it "succeeds setting the headers on DELETE" $
+        request methodDelete "/items?id=eq.11111" [] mempty
+          `shouldRespondWith` ""
+          { matchStatus = 204
+          , matchHeaders = ["X-Custom-Header" <:> "mykey=myval"]
+          }
+
+    context "Override provided headers by using GUC headers" $ do
+      it "can override the Content-Type header" $ do
+        request methodHead "/clients?id=eq.1" [] mempty
+          `shouldRespondWith` ""
+          { matchStatus = 200
+          , matchHeaders = ["Content-Type" <:> "application/geo+json"]
+          }
+        request methodHead "/rpc/getallprojects" [] mempty
+          `shouldRespondWith` ""
+          { matchStatus = 200
+          , matchHeaders = ["Content-Type" <:> "application/geo+json"]
+          }
+
+      it "can override the Location header" $
+        request methodPost "/stuff" [] [json|[{"id": 1, "name": "stuff 1"}]|]
+          `shouldRespondWith` ""
+          { matchStatus = 201
+          , matchHeaders = ["Location" <:> "/stuff?id=eq.1&overriden=true"]
+          }
+
+    -- On https://github.com/PostgREST/postgrest/issues/1427#issuecomment-595907535
+    -- it was reported that blank headers ` : ` where added and that cause proxies to fail the requests.
+    -- These tests are to ensure no blank headers are added.
+    context "Blank headers bug" $ do
+      it "shouldn't add blank headers on POST" $ do
+        r <- request methodPost "/loc_test" [] [json|{"id": "1", "c": "c1"}|]
+        liftIO $ do
+          let respHeaders = simpleHeaders r
+          respHeaders `shouldSatisfy` noBlankHeader
+
+      it "shouldn't add blank headers on PATCH" $ do
+        r <- request methodPatch "/loc_test?id=eq.1" [] [json|{"c": "c2"}|]
+        liftIO $ do
+          let respHeaders = simpleHeaders r
+          respHeaders `shouldSatisfy` noBlankHeader
+
+      it "shouldn't add blank headers on GET" $ do
+        r <- request methodGet "/loc_test" [] ""
+        liftIO $ do
+          let respHeaders = simpleHeaders r
+          respHeaders `shouldSatisfy` noBlankHeader
+
+      it "shouldn't add blank headers on DELETE" $ do
+        r <- request methodDelete "/loc_test?id=eq.1" [] ""
+        liftIO $ do
+          let respHeaders = simpleHeaders r
+          respHeaders `shouldSatisfy` noBlankHeader
+
    context "Use of the phraseto_tsquery function" $ do
      it "finds matches" $
        get "/tsearch?text_search_vector=phfts.The%20Fat%20Cats" `shouldRespondWith`
@@ -6,7 +6,7 @@ import Test.Hspec  hiding (pendingWith)
 import Protolude
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "GET / with proxy" $
    it "returns a valid openapi spec with proxy" $
@@ -11,9 +11,9 @@ import Test.Hspec.Wai.JSON
 import Protolude  hiding (get)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
-  describe "Requesting many items with server limits enabled" $ do
+  describe "Requesting many items with server limits(max-rows) enabled" $ do
    it "restricts results" $
      get "/items"
        `shouldRespondWith` [json| [{"id":1},{"id":2}] |]
@@ -29,16 +29,45 @@ spec =
          matchHeader "Content-Range" "0-0/*"
        simpleStatus r `shouldBe` ok200

-    it "limit works on all levels" $
+    it "works on all levels" $
      get "/users?select=id,tasks(id)&order=id.asc&tasks.order=id.asc"
        `shouldRespondWith` [json|[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":5},{"id":6}]}]|]
        { matchStatus  = 200
        , matchHeaders = ["Content-Range" <:> "0-1/*"]
        }

-    it "limit is not applied to parent embeds" $
-      get "/tasks?select=id,project(id)&id=gt.5"
+    it "succeeds in getting parent embeds despite the limit, see #647" $
+      get "/tasks?select=id,project:projects(id)&id=gt.5"
        `shouldRespondWith` [json|[{"id":6,"project":{"id":3}},{"id":7,"project":{"id":4}}]|]
        { matchStatus  = 200
        , matchHeaders = ["Content-Range" <:> "0-1/*"]
        }
+
+    it "can offset the parent embed, being consistent with the other embed types" $
+      get "/tasks?select=id,project:projects(id)&id=gt.5&project.offset=1"
+        `shouldRespondWith` [json|[{"id":6,"project":null}, {"id":7,"project":null}]|]
+        { matchStatus  = 200
+        , matchHeaders = ["Content-Range" <:> "0-1/*"]
+        }
+
+    context "count=estimated" $ do
+      it "uses the query planner guess when query rows > maxRows" $
+        request methodHead "/getallprojects_view" [("Prefer", "count=estimated")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-1/2019"]
+          }
+
+      it "gives exact count when query rows <= maxRows" $
+        request methodHead "/getallprojects_view?id=lt.3" [("Prefer", "count=estimated")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "0-1/2"]
+          }
+
+      it "only uses the query planner guess if it's indeed greater than the exact count" $
+        request methodHead "/get_projects_above_view" [("Prefer", "count=estimated")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-1/3"]
+          }
@@ -4,17 +4,18 @@ import Network.Wai      (Application)
 import Network.Wai.Test (SResponse (simpleHeaders))

 import Network.HTTP.Types
-import Test.Hspec
+import Test.Hspec          hiding (pendingWith)
 import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON

 import Text.Heredoc

-import Protolude  hiding (get)
+import PostgREST.Types (PgVersion, pgVersion112, pgVersion121)
+import Protolude       hiding (get)
 import SpecHelper

-spec :: SpecWith Application
-spec = do
+spec :: PgVersion -> SpecWith ((), Application)
+spec actualPgVersion = do

  describe "Querying a table with a column called count" $
    it "should not confuse count column with pg_catalog.count aggregate" $
@@ -119,6 +120,29 @@ spec = do
          [json| [ {"text_search_vector": "'ate':3 'cat':2 'fat':1 'rat':4" }] |]
          { matchHeaders = [matchContentTypeJson] }

+      when (actualPgVersion >= pgVersion112) $ do
+        it "finds matches with websearch_to_tsquery" $
+            get "/tsearch?text_search_vector=wfts.The%20Fat%20Rats" `shouldRespondWith`
+                [json| [ {"text_search_vector": "'ate':3 'cat':2 'fat':1 'rat':4" }] |]
+                { matchHeaders = [matchContentTypeJson] }
+
+        it "can use boolean operators(and, or, -) in websearch_to_tsquery" $ do
+          get "/tsearch?text_search_vector=wfts.fun%20and%20possible"
+            `shouldRespondWith`
+              [json| [ {"text_search_vector": "'also':2 'fun':3 'possibl':8"}] |]
+              { matchHeaders = [matchContentTypeJson] }
+          get "/tsearch?text_search_vector=wfts.impossible%20or%20possible"
+            `shouldRespondWith`
+              [json| [
+                {"text_search_vector": "'fun':5 'imposs':9 'kind':3"},
+                {"text_search_vector": "'also':2 'fun':3 'possibl':8"}]
+                  |]
+              { matchHeaders = [matchContentTypeJson] }
+          get "/tsearch?text_search_vector=wfts.fun%20and%20-possible"
+            `shouldRespondWith`
+              [json| [ {"text_search_vector": "'fun':5 'imposs':9 'kind':3"}] |]
+              { matchHeaders = [matchContentTypeJson] }
+
      it "finds matches with different dictionaries" $ do
        get "/tsearch?text_search_vector=fts(french).amusant" `shouldRespondWith`
          [json| [{"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4" }] |]
@@ -127,6 +151,12 @@ spec = do
          [json| [{"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4" }] |]
          { matchHeaders = [matchContentTypeJson] }

+        when (actualPgVersion >= pgVersion112) $
+            get "/tsearch?text_search_vector=wfts(french).amusant%20impossible"
+                `shouldRespondWith`
+                  [json| [{"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4" }] |]
+                  { matchHeaders = [matchContentTypeJson] }
+
      it "can be negated with not operator" $ do
        get "/tsearch?text_search_vector=not.fts.impossible%7Cfat%7Cfun" `shouldRespondWith`
          [json| [
@@ -145,6 +175,13 @@ spec = do
            {"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4"},
            {"text_search_vector": "'art':4 'spass':5 'unmog':7"}]|]
          { matchHeaders = [matchContentTypeJson] }
+        when (actualPgVersion >= pgVersion112) $
+            get "/tsearch?text_search_vector=not.wfts(english).impossible%20or%20fat%20or%20fun"
+                `shouldRespondWith`
+                  [json| [
+                    {"text_search_vector": "'amus':5 'fair':7 'impossibl':9 'peu':4"},
+                    {"text_search_vector": "'art':4 'spass':5 'unmog':7"}]|]
+                  { matchHeaders = [matchContentTypeJson] }

    it "matches with computed column" $
      get "/items?always_true=eq.true&order=id.asc" `shouldRespondWith`
@@ -161,7 +198,7 @@ spec = do

    it "matches filtering nested items 2" $
      get "/clients?select=id,projects(id,tasks2(id,name))&projects.tasks.name=like.Design*"
-        `shouldRespondWith` [json| {"message":"Could not find foreign keys between these entities, No relation found between projects and tasks2"}|]
+        `shouldRespondWith` [json| {"message":"Could not find foreign keys between these entities. No relationship found between projects and tasks2"}|]
        { matchStatus  = 400
        , matchHeaders = [matchContentTypeJson]
        }
@@ -200,7 +237,6 @@ spec = do
        [json| [{"myId":1}] |]
        { matchHeaders = [matchContentTypeJson] }

-
    it "one simple column with casting (text)" $
      get "/complex_items?select=id::text" `shouldRespondWith`
        [json| [{"id":"1"},{"id":"2"},{"id":"3"}] |]
@@ -228,19 +264,8 @@ spec = do
        [json|[{"id":1,"name":"Windows 7","clients":{"id":1,"name":"Microsoft"},"tasks":[{"id":1,"name":"Design w7"},{"id":2,"name":"Code w7"}]}]|]
        { matchHeaders = [matchContentTypeJson] }

-    it "requesting parent without specifying primary key" $
-      get "/projects?select=name,client(name)" `shouldRespondWith`
-        [json|[
-          {"name":"Windows 7","client":{"name": "Microsoft"}},
-          {"name":"Windows 10","client":{"name": "Microsoft"}},
-          {"name":"IOS","client":{"name": "Apple"}},
-          {"name":"OSX","client":{"name": "Apple"}},
-          {"name":"Orphan","client":null}
-        ]|]
-        { matchHeaders = [matchContentTypeJson] }
-
    it "requesting parent and renaming primary key" $
-      get "/projects?select=name,client(clientId:id,name)" `shouldRespondWith`
+      get "/projects?select=name,client:clients(clientId:id,name)" `shouldRespondWith`
        [json|[
          {"name":"Windows 7","client":{"name": "Microsoft", "clientId": 1}},
          {"name":"Windows 10","client":{"name": "Microsoft", "clientId": 1}},
@@ -258,24 +283,11 @@ spec = do
        [json|[{"id":1,"commenter_id":1,"user_id":2,"task_id":6,"content":"Needs to be delivered ASAP","users_tasks":{"taskId": 6}}]|]
        { matchHeaders = [matchContentTypeJson] }

-    it "embed data with two fk pointing to the same table" $
-      get "/orders?id=eq.1&select=id, name, billing_address_id(id), shipping_address_id(id)" `shouldRespondWith`
-        [str|[{"id":1,"name":"order 1","billing_address_id":{"id":1},"shipping_address_id":{"id":2}}]|]
-
-
    it "requesting parents and children while renaming them" $
-      get "/projects?id=eq.1&select=myId:id, name, project_client:client_id(*), project_tasks:tasks(id, name)" `shouldRespondWith`
+      get "/projects?id=eq.1&select=myId:id, name, project_client:clients(*), project_tasks:tasks(id, name)" `shouldRespondWith`
        [json|[{"myId":1,"name":"Windows 7","project_client":{"id":1,"name":"Microsoft"},"project_tasks":[{"id":1,"name":"Design w7"},{"id":2,"name":"Code w7"}]}]|]
        { matchHeaders = [matchContentTypeJson] }

-    it "requesting parents two levels up while using FK to specify the link" $
-      get "/tasks?id=eq.1&select=id,name,project:project_id(id,name,client:client_id(id,name))" `shouldRespondWith`
-        [str|[{"id":1,"name":"Design w7","project":{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}}}]|]
-
-    it "requesting parents two levels up while using FK to specify the link (with rename)" $
-      get "/tasks?id=eq.1&select=id,name,project:project_id(id,name,client:client_id(id,name))" `shouldRespondWith`
-        [str|[{"id":1,"name":"Design w7","project":{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}}}]|]
-
    it "requesting parents and filtering parent columns" $
      get "/projects?id=eq.1&select=id, name, clients(id)" `shouldRespondWith`
        [str|[{"id":1,"name":"Windows 7","clients":{"id":1}}]|]
@@ -314,20 +326,29 @@ spec = do
        [json|[{"user_id":2,"task_id":6,"comments":[{"content":"Needs to be delivered ASAP"}]}]|]
        { matchHeaders = [matchContentTypeJson] }

-    it "can embed by FK column name" $
-      get "/projects?id=in.(1,3)&select=id,name,client_id(id,name)" `shouldRespondWith`
-        [json|[{"id":1,"name":"Windows 7","client_id":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":{"id":2,"name":"Apple"}}]|]
-        { matchHeaders = [matchContentTypeJson] }
+    describe "computed columns" $ do
+      it "computed column on table" $
+        get "/items?id=eq.1&select=id,always_true" `shouldRespondWith`
+          [json|[{"id":1,"always_true":true}]|]
+          { matchHeaders = [matchContentTypeJson] }

-    it "can embed by FK column name and select the FK value at the same time, if aliased" $
-      get "/projects?id=in.(1,3)&select=id,name,client_id,client:client_id(id,name)" `shouldRespondWith`
-        [json|[{"id":1,"name":"Windows 7","client_id":1,"client":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":2,"client":{"id":2,"name":"Apple"}}]|]
-        { matchHeaders = [matchContentTypeJson] }
+      it "computed column on rpc" $
+        get "/rpc/search?id=1&select=id,always_true" `shouldRespondWith`
+          [json|[{"id":1,"always_true":true}]|]
+          { matchHeaders = [matchContentTypeJson] }

-    it "can select by column name sans id" $
-      get "/projects?id=in.(1,3)&select=id,name,client_id,client(id,name)" `shouldRespondWith`
-        [json|[{"id":1,"name":"Windows 7","client_id":1,"client":{"id":1,"name":"Microsoft"}},{"id":3,"name":"IOS","client_id":2,"client":{"id":2,"name":"Apple"}}]|]
-        { matchHeaders = [matchContentTypeJson] }
+      it "overloaded computed columns on both tables" $ do
+        get "/items?id=eq.1&select=id,computed_overload" `shouldRespondWith`
+          [json|[{"id":1,"computed_overload":true}]|]
+          { matchHeaders = [matchContentTypeJson] }
+        get "/items2?id=eq.1&select=id,computed_overload" `shouldRespondWith`
+          [json|[{"id":1,"computed_overload":true}]|]
+          { matchHeaders = [matchContentTypeJson] }
+
+      it "overloaded computed column on rpc" $
+        get "/rpc/search?id=1&select=id,computed_overload" `shouldRespondWith`
+          [json|[{"id":1,"computed_overload":true}]|]
+          { matchHeaders = [matchContentTypeJson] }

    describe "view embedding" $ do
      it "can detect fk relations through views to tables in the public schema" $
@@ -336,8 +357,8 @@ spec = do
      it "can detect fk relations through materialized views to tables in the public schema" $
        get "/materialized_projects?select=*,users(*)" `shouldRespondWith` 200

-      it "can request parent without specifying primary key" $
-        get "/articleStars?select=createdAt,article(owner),user(name)&limit=1" `shouldRespondWith`
+      it "can request two parents" $
+        get "/articleStars?select=createdAt,article:articles(owner),user:users(name)&limit=1" `shouldRespondWith`
          [json|[{"createdAt":"2015-12-08T04:22:57.472738","article":{"owner": "postgrest_test_authenticator"},"user":{"name": "Angela Martin"}}]|]
          { matchHeaders = [matchContentTypeJson] }

@@ -357,16 +378,16 @@ spec = do
          { matchHeaders = [matchContentTypeJson] }

      it "detects parent relations when having many views of a private table" $ do
-        get "/books?select=title,author(name)&id=eq.5" `shouldRespondWith`
+        get "/books?select=title,author:authors(name)&id=eq.5" `shouldRespondWith`
          [json|[ { "title": "Farenheit 451", "author": { "name": "Ray Bradbury" } } ]|]
          { matchHeaders = [matchContentTypeJson] }
-        get "/forties_books?select=title,author(name)&limit=1" `shouldRespondWith`
+        get "/forties_books?select=title,author:authors(name)&limit=1" `shouldRespondWith`
          [json|[ { "title": "1984", "author": { "name": "George Orwell" } } ]|]
          { matchHeaders = [matchContentTypeJson] }
-        get "/fifties_books?select=title,author(name)&limit=1" `shouldRespondWith`
+        get "/fifties_books?select=title,author:authors(name)&limit=1" `shouldRespondWith`
          [json|[ { "title": "The Catcher in the Rye", "author": { "name": "J.D. Salinger" } } ]|]
          { matchHeaders = [matchContentTypeJson] }
-        get "/sixties_books?select=title,author(name)&limit=1" `shouldRespondWith`
+        get "/sixties_books?select=title,author:authors(name)&limit=1" `shouldRespondWith`
          [json|[ { "title": "To Kill a Mockingbird", "author": { "name": "Harper Lee" } } ]|]
          { matchHeaders = [matchContentTypeJson] }

@@ -429,7 +450,7 @@ spec = do
          { matchHeaders = [matchContentTypeJson] }

      it "can embed a view that has group by" $
-        get "/projects_count_grouped_by?select=number_of_projects,client(name)&order=number_of_projects" `shouldRespondWith`
+        get "/projects_count_grouped_by?select=number_of_projects,client:clients(name)&order=number_of_projects" `shouldRespondWith`
          [json|
            [{"number_of_projects":1,"client":null},
             {"number_of_projects":2,"client":{"name":"Microsoft"}},
@@ -441,48 +462,6 @@ spec = do
          [json| [{"name":"George Orwell","entities":[3, 4],"books":[{"title":"1984"}]}] |]
          { matchHeaders = [matchContentTypeJson] }

-    describe "path fixed" $ do
-      it "works when requesting children 2 levels" $
-        get "/clients?id=eq.1&select=id,projects:projects%2Bclient_id(id,tasks(id))" `shouldRespondWith`
-          [json|[{"id":1,"projects":[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":3},{"id":4}]}]}]|]
-          { matchHeaders = [matchContentTypeJson] }
-
-      it "works with parent relation" $
-        get "/message?select=id,body,sender:person%2Bsender(name),recipient:person%2Brecipient(name)&id=lt.4" `shouldRespondWith`
-          [json|
-            [{"id":1,"body":"Hello Jane","sender":{"name":"John"},"recipient":{"name":"Jane"}},
-             {"id":2,"body":"Hi John","sender":{"name":"Jane"},"recipient":{"name":"John"}},
-             {"id":3,"body":"How are you doing?","sender":{"name":"John"},"recipient":{"name":"Jane"}}] |]
-          { matchHeaders = [matchContentTypeJson] }
-
-      it "fails with an unknown relation" $
-        get "/message?select=id,sender:person.space(name)&id=lt.4" `shouldRespondWith`
-          [json|{"message":"Could not find foreign keys between these entities, No relation found between message and person"}|]
-          { matchStatus = 400
-          , matchHeaders = [matchContentTypeJson] }
-
-      it "works with a parent view relation" $
-        get "/message?select=id,body,sender:person_detail%2Bsender(name,sent),recipient:person_detail%2Brecipient(name,received)&id=lt.4" `shouldRespondWith`
-          [json|
-            [{"id":1,"body":"Hello Jane","sender":{"name":"John","sent":2},"recipient":{"name":"Jane","received":2}},
-             {"id":2,"body":"Hi John","sender":{"name":"Jane","sent":1},"recipient":{"name":"John","received":1}},
-             {"id":3,"body":"How are you doing?","sender":{"name":"John","sent":2},"recipient":{"name":"Jane","received":2}}] |]
-          { matchHeaders = [matchContentTypeJson] }
-
-      it "works with many<->many relation" $
-        get "/tasks?select=id,users:users%2Busers_tasks(id)" `shouldRespondWith`
-          [json|[{"id":1,"users":[{"id":1},{"id":3}]},{"id":2,"users":[{"id":1}]},{"id":3,"users":[{"id":1}]},{"id":4,"users":[{"id":1}]},{"id":5,"users":[{"id":2},{"id":3}]},{"id":6,"users":[{"id":2}]},{"id":7,"users":[{"id":2}]},{"id":8,"users":[]}]|]
-          { matchHeaders = [matchContentTypeJson] }
-
-      describe "old dot '.' symbol, deprecated" $
-        it "still works" $ do
-          get "/clients?id=eq.1&select=id,projects:projects.client_id(id,tasks(id))" `shouldRespondWith`
-            [json|[{"id":1,"projects":[{"id":1,"tasks":[{"id":1},{"id":2}]},{"id":2,"tasks":[{"id":3},{"id":4}]}]}]|]
-            { matchHeaders = [matchContentTypeJson] }
-          get "/tasks?select=id,users:users.users_tasks(id)" `shouldRespondWith`
-            [json|[{"id":1,"users":[{"id":1},{"id":3}]},{"id":2,"users":[{"id":1}]},{"id":3,"users":[{"id":1}]},{"id":4,"users":[{"id":1}]},{"id":5,"users":[{"id":2},{"id":3}]},{"id":6,"users":[{"id":2}]},{"id":7,"users":[{"id":2}]},{"id":8,"users":[]}]|]
-            { matchHeaders = [matchContentTypeJson] }
-
    describe "aliased embeds" $ do
      it "works with child relation" $
        get "/space?select=id,zones:zone(id,name),stores:zone(id,name)&zones.zone_type_id=eq.2&stores.zone_type_id=eq.3" `shouldRespondWith`
@@ -526,128 +505,20 @@ spec = do
              "designTasks":[ ] }
          ]|] { matchHeaders = [matchContentTypeJson] }

-      it "works with two aliased childs embeds plus and/or" $
-        get "/entities?select=id,childs:child_entities(id,gChilds:grandchild_entities(id))&childs.and=(id.in.(1,2,3))&childs.gChilds.or=(id.eq.1,id.eq.2)" `shouldRespondWith`
+      it "works with two aliased children embeds plus and/or" $
+        get "/entities?select=id,children:child_entities(id,gChildren:grandchild_entities(id))&children.and=(id.in.(1,2,3))&children.gChildren.or=(id.eq.1,id.eq.2)" `shouldRespondWith`
          [json|[
            { "id":1,
-              "childs":[
-                {"id":1,"gChilds":[{"id":1}, {"id":2}]},
-                {"id":2,"gChilds":[]}]},
+              "children":[
+                {"id":1,"gChildren":[{"id":1}, {"id":2}]},
+                {"id":2,"gChildren":[]}]},
            { "id":2,
-              "childs":[
-                {"id":3,"gChilds":[]}]},
-            { "id":3,"childs":[]},
-            { "id":4,"childs":[]}
+              "children":[
+                {"id":3,"gChildren":[]}]},
+            { "id":3,"children":[]},
+            { "id":4,"children":[]}
          ]|] { matchHeaders = [matchContentTypeJson] }

-    describe "tables with self reference foreign keys" $ do
-      context "one self reference foreign key" $ do
-        it "embeds parents recursively" $
-          get "/family_tree?id=in.(3,4)&select=id,parent(id,name,parent(*))" `shouldRespondWith`
-            [json|[
-              { "id": "3", "parent": { "id": "1", "name": "Parental Unit", "parent": null } },
-              { "id": "4", "parent": { "id": "2", "name": "Kid One", "parent": { "id": "1", "name": "Parental Unit", "parent": null } } }
-            ]|]
-            { matchHeaders = [matchContentTypeJson] }
-
-        it "embeds childs recursively" $
-          get "/family_tree?id=eq.1&select=id,name, childs:family_tree%2Bparent(id,name,childs:family_tree%2Bparent(id,name))" `shouldRespondWith`
-            [json|[{
-              "id": "1", "name": "Parental Unit", "childs": [
-                { "id": "2", "name": "Kid One", "childs": [ { "id": "4", "name": "Grandkid One" } ] },
-                { "id": "3", "name": "Kid Two", "childs": [ { "id": "5", "name": "Grandkid Two" } ] }
-              ]
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
-        it "embeds parent and then embeds childs" $
-          get "/family_tree?id=eq.2&select=id,name,parent(id,name,childs:family_tree%2Bparent(id,name))" `shouldRespondWith`
-            [json|[{
-              "id": "2", "name": "Kid One", "parent": {
-                "id": "1", "name": "Parental Unit", "childs": [ { "id": "2", "name": "Kid One" }, { "id": "3", "name": "Kid Two"} ]
-              }
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
-      context "two self reference foreign keys" $ do
-        it "embeds parents" $
-          get "/organizations?select=id,name,referee(id,name),auditor(id,name)&id=eq.3" `shouldRespondWith`
-            [json|[{
-              "id": 3, "name": "Acme",
-              "referee": {
-                "id": 1,
-                "name": "Referee Org"
-              },
-              "auditor": {
-                "id": 2,
-                "name": "Auditor Org"
-              }
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
-        it "embeds childs" $ do
-          get "/organizations?select=id,name,refereeds:organizations%2Breferee(id,name)&id=eq.1" `shouldRespondWith`
-            [json|[{
-              "id": 1, "name": "Referee Org",
-              "refereeds": [
-                {
-                  "id": 3,
-                  "name": "Acme"
-                },
-                {
-                  "id": 4,
-                  "name": "Umbrella"
-                }
-              ]
-            }]|] { matchHeaders = [matchContentTypeJson] }
-          get "/organizations?select=id,name,auditees:organizations%2Bauditor(id,name)&id=eq.2" `shouldRespondWith`
-            [json|[{
-              "id": 2, "name": "Auditor Org",
-              "auditees": [
-                {
-                  "id": 3,
-                  "name": "Acme"
-                },
-                {
-                  "id": 4,
-                  "name": "Umbrella"
-                }
-              ]
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
-        it "embeds other relations(manager) besides the self reference" $ do
-          get "/organizations?select=name,manager(name),referee(name,manager(name),auditor(name,manager(name))),auditor(name,manager(name),referee(name,manager(name)))&id=eq.5" `shouldRespondWith`
-            [json|[{
-              "name":"Cyberdyne",
-              "manager":{"name":"Cyberdyne Manager"},
-              "referee":{
-                "name":"Acme",
-                "manager":{"name":"Acme Manager"},
-                "auditor":{
-                  "name":"Auditor Org",
-                  "manager":{"name":"Auditor Manager"}}},
-              "auditor":{
-                "name":"Umbrella",
-                "manager":{"name":"Umbrella Manager"},
-                "referee":{
-                  "name":"Referee Org",
-                  "manager":{"name":"Referee Manager"}}}
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
-          get "/organizations?select=name,manager(name),auditees:organizations%2Bauditor(name,manager(name),refereeds:organizations%2Breferee(name,manager(name)))&id=eq.2" `shouldRespondWith`
-            [json|[{
-              "name":"Auditor Org",
-              "manager":{"name":"Auditor Manager"},
-              "auditees":[
-                {"name":"Acme",
-                 "manager":{"name":"Acme Manager"},
-                 "refereeds":[
-                   {"name":"Cyberdyne",
-                    "manager":{"name":"Cyberdyne Manager"}},
-                   {"name":"Oscorp",
-                    "manager":{"name":"Oscorp Manager"}}]},
-                {"name":"Umbrella",
-                 "manager":{"name":"Umbrella Manager"},
-                 "refereeds":[]}]
-            }]|] { matchHeaders = [matchContentTypeJson] }
-
  describe "ordering response" $ do
    it "by a column asc" $
      get "/items?id=lte.2&order=id.asc"
@@ -743,10 +614,6 @@ spec = do
      get "/projects?id=eq.1&select=id, name, clients(id, name)&clients.order=name.asc" `shouldRespondWith`
        [str|[{"id":1,"name":"Windows 7","clients":{"id":1,"name":"Microsoft"}}]|]

-    it "ordering embeded parents does not break things when using ducktape names" $
-      get "/projects?id=eq.1&select=id, name, client(id, name)&client.order=name.asc" `shouldRespondWith`
-        [str|[{"id":1,"name":"Windows 7","client":{"id":1,"name":"Microsoft"}}]|]
-
    context "order syntax errors" $ do
      it "gives meaningful error messages when asc/desc/nulls{first,last} are misspelled" $ do
        get "/items?order=id.ac" `shouldRespondWith`
@@ -876,11 +743,6 @@ spec = do
        [json| [{"ghostBusters":[{"escapeId":1}]},{"ghostBusters":[]},{"ghostBusters":[{"escapeId":3}]},{"ghostBusters":[]},{"ghostBusters":[{"escapeId":5}]}] |]
        { matchHeaders = [matchContentTypeJson] }

-    it "will embed using a column" $
-      get "/ghostBusters?select=escapeId(*)" `shouldRespondWith`
-        [json| [{"escapeId":{"so6meIdColumn":1}},{"escapeId":{"so6meIdColumn":3}},{"escapeId":{"so6meIdColumn":5}}] |]
-        { matchHeaders = [matchContentTypeJson] }
-
    it "will select and filter a column that has spaces" $
      get "/Server%20Today?select=Just%20A%20Server%20Model&Just%20A%20Server%20Model=like.*91*" `shouldRespondWith`
        [json|[
@@ -913,7 +775,7 @@ spec = do
    it "fails if a single column is not selected" $ do
      request methodGet "/images?select=img,name&name=eq.A.png" (acceptHdrs "application/octet-stream") ""
        `shouldRespondWith`
-        [json| {"message":"application/octet-stream requested but a single column was not selected"} |]
+        [json| {"message":"application/octet-stream requested but more than one column was selected"} |]
        { matchStatus = 406
        , matchHeaders = [matchContentTypeJson]
        }
@@ -929,58 +791,6 @@ spec = do
        , matchHeaders = ["Content-Type" <:> "application/octet-stream; charset=utf-8"]
        }

-  describe "HTTP request env vars" $ do
-    it "custom header is set" $
-      request methodPost "/rpc/get_guc_value"
-                [("Custom-Header", "test")]
-          [json| { "name": "request.header.custom-header" } |]
-          `shouldRespondWith`
-          [str|"test"|]
-          { matchStatus  = 200
-          , matchHeaders = [ matchContentTypeJson ]
-          }
-    it "standard header is set" $
-      request methodPost "/rpc/get_guc_value"
-                [("Origin", "http://example.com")]
-          [json| { "name": "request.header.origin" } |]
-          `shouldRespondWith`
-          [str|"http://example.com"|]
-          { matchStatus  = 200
-          , matchHeaders = [ matchContentTypeJson ]
-          }
-    it "current role is available as GUC claim" $
-      request methodPost "/rpc/get_guc_value" []
-          [json| { "name": "request.jwt.claim.role" } |]
-          `shouldRespondWith`
-          [str|"postgrest_test_anonymous"|]
-          { matchStatus  = 200
-          , matchHeaders = [ matchContentTypeJson ]
-          }
-    it "single cookie ends up as claims" $
-      request methodPost "/rpc/get_guc_value" [("Cookie","acookie=cookievalue")]
-        [json| {"name":"request.cookie.acookie"} |]
-          `shouldRespondWith`
-          [str|"cookievalue"|]
-          { matchStatus = 200
-          , matchHeaders = []
-          }
-    it "multiple cookies ends up as claims" $
-      request methodPost "/rpc/get_guc_value" [("Cookie","acookie=cookievalue;secondcookie=anothervalue")]
-        [json| {"name":"request.cookie.secondcookie"} |]
-          `shouldRespondWith`
-          [str|"anothervalue"|]
-          { matchStatus = 200
-          , matchHeaders = []
-          }
-    it "app settings available" $
-      request methodPost "/rpc/get_guc_value" []
-        [json| { "name": "app.settings.app_host" } |]
-          `shouldRespondWith`
-          [str|"localhost"|]
-          { matchStatus  = 200
-          , matchHeaders = [ matchContentTypeJson ]
-          }
-
  describe "values with quotes in IN and NOT IN" $ do
    it "succeeds when only quoted values are present" $ do
      get "/w_or_wo_comma_names?name=in.(\"Hebdon, John\")" `shouldRespondWith`
@@ -1046,8 +856,12 @@ spec = do

    it "only returns an empty result set if the in value is empty" $
      get "/items_with_different_col_types?int_data=in.( ,3,4)"
-        `shouldRespondWith`
+        `shouldRespondWith` (
+        if actualPgVersion >= pgVersion121 then
+        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for type integer: \"\""} |]
+        else
        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"\""} |]
+                            )
        { matchStatus = 400
        , matchHeaders = [matchContentTypeJson]
        }
@@ -1074,3 +888,18 @@ spec = do

  it "cannot use ltree(in public schema) extension operators if no extra search path added" $
    get "/ltree_sample?path=cd.Top.Science.Astronomy" `shouldRespondWith` 400
+
+  context "VIEW that has a source FK based on a UNIQUE key" $
+    it "can be embedded" $
+      get "/referrals?select=site,link:pages(url)" `shouldRespondWith`
+        [json| [
+         {"site":"github.com",     "link":{"url":"http://postgrest.org/en/v6.0/api.html"}},
+         {"site":"hub.docker.com", "link":{"url":"http://postgrest.org/en/v6.0/admin.html"}}
+        ]|]
+        { matchHeaders = [matchContentTypeJson] }
+
+  it "shouldn't produce a Content-Profile header since only a single schema is exposed" $ do
+    r <- get "/items"
+    liftIO $ do
+      let respHeaders = simpleHeaders r
+      respHeaders `shouldSatisfy` noProfileHeader
@@ -19,7 +19,7 @@ defaultRange = [json| { "min": 0, "max": 15 } |]
 emptyRange :: BL.ByteString
 emptyRange = [json| { "min": 2, "max": 2 } |]

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = do
  describe "POST /rpc/getitemrange" $ do
    context "without range headers" $ do
@@ -155,12 +155,17 @@ spec = do
          , matchHeaders = ["Content-Range" <:> "0-0/*"]
          }

-      it "limit and offset works on first level" $
+      it "limit and offset works on first level" $ do
        get "/items?select=id&order=id.asc&limit=3&offset=2"
          `shouldRespondWith` [json|[{"id":3},{"id":4},{"id":5}]|]
          { matchStatus  = 200
          , matchHeaders = ["Content-Range" <:> "2-4/*"]
          }
+        request methodHead "/items?select=id&order=id.asc&limit=3&offset=2" [] mempty
+          `shouldRespondWith` ""
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "2-4/*"]
+          }

      it "succeeds if offset equals 0 as a no-op" $
        get "/items?select=id&offset=0"
@@ -192,6 +197,65 @@ spec = do
          , matchHeaders = [matchContentTypeJson]
          }

+    context "when count=planned" $ do
+      it "obtains a filtered range" $ do
+        request methodGet "/items?select=id&id=gt.8" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` [json|[{"id":9}, {"id":10}, {"id":11}, {"id":12}, {"id":13}, {"id":14}, {"id":15}]|]
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-6/8"]
+          }
+        request methodGet "/child_entities?select=id&id=gt.3" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` [json|[{"id":4}, {"id":5}, {"id":6}]|]
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-2/4"]
+          }
+        request methodGet "/getallprojects_view?select=id&id=lt.3" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` [json|[{"id":1}, {"id":2}]|]
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-1/673"]
+          }
+
+      it "obtains the full range" $ do
+        request methodHead "/items" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "0-14/15"]
+          }
+        request methodHead "/child_entities" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "0-5/6"]
+          }
+        request methodHead "/getallprojects_view" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-4/2019"]
+          }
+
+      it "ignores limit/offset on the planned count" $ do
+        request methodHead "/items?limit=2&offset=3" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "3-4/15"]
+          }
+        request methodHead "/child_entities?limit=2" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-1/6"]
+          }
+        request methodHead "/getallprojects_view?limit=2" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 206
+          , matchHeaders = ["Content-Range" <:> "0-1/2019"]
+          }
+
+      it "works with two levels" $
+        request methodHead "/child_entities?select=*,entities(*)" [("Prefer", "count=planned")] ""
+          `shouldRespondWith` ""
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "0-5/6"]
+          }
+
    context "with range headers" $ do
      context "of acceptable range" $ do
        it "succeeds with partial content" $ do
@@ -0,0 +1,33 @@
+module Feature.RawOutputTypesSpec where
+
+import Network.Wai (Application)
+
+import Network.HTTP.Types
+import Test.Hspec
+import Test.Hspec.Wai
+import Test.Hspec.Wai.JSON
+
+import Protolude
+import SpecHelper (acceptHdrs)
+
+spec :: SpecWith ((), Application)
+spec = describe "When raw-media-types config variable is missing or left empty" $ do
+  let firefoxAcceptHdrs = acceptHdrs "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
+      chromeAcceptHdrs = acceptHdrs "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3"
+  it "responds json to a GET request with Firefox Accept headers" $
+    request methodGet "/items?id=eq.1" firefoxAcceptHdrs ""
+      `shouldRespondWith` [json| [{"id":1}] |]
+        { matchHeaders= ["Content-Type" <:> "application/json; charset=utf-8"] }
+  it "responds json to a GET request with Chrome Accept headers" $
+    request methodGet "/items?id=eq.1" chromeAcceptHdrs ""
+      `shouldRespondWith` [json| [{"id":1}] |]
+        { matchHeaders= ["Content-Type" <:> "application/json; charset=utf-8"] }
+
+  it "responds json to a GET request to RPC with Firefox Accept headers" $
+    request methodGet "/rpc/get_projects_below?id=3" chromeAcceptHdrs ""
+      `shouldRespondWith` [json|[{"id":1,"name":"Windows 7","client_id":1}, {"id":2,"name":"Windows 10","client_id":1}]|]
+        { matchHeaders= ["Content-Type" <:> "application/json; charset=utf-8"] }
+  it "responds json to a GET request to RPC with Chrome Accept headers" $
+    request methodGet "/rpc/get_projects_below?id=3" chromeAcceptHdrs ""
+      `shouldRespondWith` [json|[{"id":1,"name":"Windows 7","client_id":1}, {"id":2,"name":"Windows 10","client_id":1}]|]
+        { matchHeaders= ["Content-Type" <:> "application/json; charset=utf-8"] }
@@ -11,7 +11,7 @@ import Protolude hiding (get)

 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "root spec function" $ do
    it "accepts application/openapi+json" $
@@ -11,12 +11,13 @@ import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON
 import Text.Heredoc

-import PostgREST.Types (PgVersion, pgVersion100, pgVersion95,
-                        pgVersion96)
+import PostgREST.Types (PgVersion, pgVersion100, pgVersion109,
+                        pgVersion110, pgVersion112, pgVersion114,
+                        pgVersion95)
 import Protolude       hiding (get)
 import SpecHelper

-spec :: PgVersion -> SpecWith Application
+spec :: PgVersion -> SpecWith ((), Application)
 spec actualPgVersion =
  describe "remote procedure call" $ do
    context "a proc that returns a set" $ do
@@ -33,6 +34,12 @@ spec actualPgVersion =
            { matchStatus = 200
            , matchHeaders = ["Content-Range" <:> "0-0/*"]
            }
+        request methodHead "/rpc/getitemrange?min=2&max=4"
+                (rangeHdrs (ByteRangeFromTo 0 0)) ""
+           `shouldRespondWith` ""
+            { matchStatus = 200
+            , matchHeaders = ["Content-Range" <:> "0-0/*"]
+            }

      it "includes total count if requested" $ do
        request methodPost "/rpc/getitemrange"
@@ -48,6 +55,12 @@ spec actualPgVersion =
            { matchStatus = 206
            , matchHeaders = ["Content-Range" <:> "0-0/2"]
            }
+        request methodHead "/rpc/getitemrange?min=2&max=4"
+                (rangeHdrsWithCount (ByteRangeFromTo 0 0)) ""
+           `shouldRespondWith` ""
+            { matchStatus = 206
+            , matchHeaders = ["Content-Range" <:> "0-0/2"]
+            }

      it "returns proper json" $ do
        post "/rpc/getitemrange" [json| { "min": 2, "max": 4 } |] `shouldRespondWith`
@@ -71,6 +84,12 @@ spec actualPgVersion =
            { matchStatus = 200
            , matchHeaders = ["Content-Type" <:> "text/csv; charset=utf-8"]
            }
+        request methodHead "/rpc/getitemrange?min=2&max=4"
+                (acceptHdrs "text/csv") ""
+           `shouldRespondWith` ""
+            { matchStatus = 200
+            , matchHeaders = ["Content-Type" <:> "text/csv; charset=utf-8"]
+            }

    context "unknown function" $ do
      it "returns 404" $
@@ -139,10 +158,10 @@ spec actualPgVersion =

    context "foreign entities embedding" $ do
      it "can embed if related tables are in the exposed schema" $ do
-        post "/rpc/getproject?select=id,name,client(id),tasks(id)" [json| { "id": 1} |] `shouldRespondWith`
+        post "/rpc/getproject?select=id,name,client:clients(id),tasks(id)" [json| { "id": 1} |] `shouldRespondWith`
          [json|[{"id":1,"name":"Windows 7","client":{"id":1},"tasks":[{"id":1},{"id":2}]}]|]
          { matchHeaders = [matchContentTypeJson] }
-        get "/rpc/getproject?id=1&select=id,name,client(id),tasks(id)" `shouldRespondWith`
+        get "/rpc/getproject?id=1&select=id,name,client:clients(id),tasks(id)" `shouldRespondWith`
          [json|[{"id":1,"name":"Windows 7","client":{"id":1},"tasks":[{"id":1},{"id":2}]}]|]
          { matchHeaders = [matchContentTypeJson] }

@@ -160,6 +179,29 @@ spec actualPgVersion =
          `shouldRespondWith` [json|[{"id": 2, "articleStars": [{"userId": 3}]}]|]
          { matchHeaders = [matchContentTypeJson] }

+      it "can embed an M2M relationship table" $
+        get "/rpc/getallusers?select=name,tasks(name)&id=gt.1"
+          `shouldRespondWith` [json|[
+            {"name":"Michael Scott", "tasks":[{"name":"Design IOS"}, {"name":"Code IOS"}, {"name":"Design OSX"}]},
+            {"name":"Dwight Schrute","tasks":[{"name":"Design w7"}, {"name":"Design IOS"}]}
+          ]|]
+          { matchHeaders = [matchContentTypeJson] }
+
+      it "can embed an M2M relationship table that has a parent relationship table" $
+        get "/rpc/getallusers?select=name,tasks(name,project:projects(name))&id=gt.1"
+          `shouldRespondWith` [json|[
+            {"name":"Michael Scott","tasks":[
+              {"name":"Design IOS","project":{"name":"IOS"}},
+              {"name":"Code IOS","project":{"name":"IOS"}},
+              {"name":"Design OSX","project":{"name":"OSX"}}
+            ]},
+            {"name":"Dwight Schrute","tasks":[
+              {"name":"Design w7","project":{"name":"Windows 7"}},
+              {"name":"Design IOS","project":{"name":"IOS"}}
+            ]}
+          ]|]
+          { matchHeaders = [matchContentTypeJson] }
+
    context "a proc that returns an empty rowset" $
      it "returns empty json array" $ do
        post "/rpc/test_empty_rowset" [json| {} |] `shouldRespondWith`
@@ -256,38 +298,23 @@ spec actualPgVersion =
            [json|"object"|]
            { matchHeaders = [matchContentTypeJson] }

-      when (actualPgVersion <= pgVersion96) $
-        it "parses quoted JSON arguments as JSON (Postgres <= 9.6)" $
+      when (actualPgVersion < pgVersion100) $
+        it "parses quoted JSON arguments as JSON (Postgres < 10)" $
          post "/rpc/json_argument"
              [json| { "arg": "{ \"key\": 3 }" } |]
            `shouldRespondWith`
              [json|"object"|]
              { matchHeaders = [matchContentTypeJson] }

-      when (actualPgVersion >= pgVersion100) $ do
-        it "parses quoted JSON arguments as JSON string (Postgres >= 10)" $ do
-          -- Postgres bug report:
-          -- https://www.postgresql.org/message-id/D6921B37-BD8E-4664-8D5F-DB3525765DCD%40vllmrt.net
-          -- * json_to_record fails (see following test)
-          -- * jsonb_to_record parses the embedded quoted JSON to a JSON string,
-          --   so that's probably the expected behavior for Postgres >= 10
-          pendingWith "Postgres >= 10 fails to parse quoted embedded JSON"
+      when ((actualPgVersion >= pgVersion109 && actualPgVersion < pgVersion110)
+            || actualPgVersion >= pgVersion114) $
+        it "parses quoted JSON arguments as JSON string (from Postgres 10.9, 11.4)" $
          post "/rpc/json_argument"
              [json| { "arg": "{ \"key\": 3 }" } |]
            `shouldRespondWith`
              [json|"string"|]
              { matchHeaders = [matchContentTypeJson] }

-        it "fails to parse quoted JSON arguments (Postgres >= 10)" $
-          -- Confirming buggy Postgres behavior (see previous test)
-          post "/rpc/json_argument"
-              [json| { "arg": "{ \"key\": 3 }" } |]
-            `shouldRespondWith`
-              [json|{"hint":null,"details":"Token \"key\" is invalid.","code":"22P02","message":"invalid input syntax for type json"}|]
-              { matchStatus  = 400
-              , matchHeaders = [matchContentTypeJson]
-              }
-
    context "improper input" $ do
      it "rejects unknown content type even if payload is good" $ do
        request methodPost "/rpc/sayhello"
@@ -429,24 +456,34 @@ spec actualPgVersion =

      it "ignores json keys not included in ?columns" $
        post "/rpc/sayhello?columns=name"
-          [json|{"name": "John", "smth": "here", "other": "stuff", "fake_id": 13}|] `shouldRespondWith`
+          [json|{"name": "John", "smth": "here", "other": "stuff", "fake_id": 13}|]
+          `shouldRespondWith`
          [json|"Hello, John"|]
          { matchHeaders = [matchContentTypeJson] }

-    context "bulk RPC" $ do
-      it "works with a scalar function an returns a json array" $
+      it "only takes the first object in case of array of objects payload" $
        post "/rpc/add_them"
          [json|[
            {"a": 1, "b": 2},
            {"a": 4, "b": 6},
-            {"a": 100, "b": 200}
-          ]|] `shouldRespondWith`
+            {"a": 100, "b": 200} ]|]
+          `shouldRespondWith` "3"
+          { matchHeaders = [matchContentTypeJson] }
+
+    context "bulk RPC with params=multiple-objects" $ do
+      it "works with a scalar function an returns a json array" $
+        request methodPost "/rpc/add_them" [("Prefer", "params=multiple-objects")]
+          [json|[
+            {"a": 1, "b": 2},
+            {"a": 4, "b": 6},
+            {"a": 100, "b": 200} ]|]
+          `shouldRespondWith`
          [json|
            [3, 10, 300]
          |] { matchHeaders = [matchContentTypeJson] }

      it "works with a scalar function an returns a json array when posting CSV" $
-        request methodPost "/rpc/add_them" [("Content-Type", "text/csv")]
+        request methodPost "/rpc/add_them" [("Content-Type", "text/csv"), ("Prefer", "params=multiple-objects")]
          "a,b\n1,2\n4,6\n100,200"
          `shouldRespondWith`
          [json|
@@ -457,11 +494,11 @@ spec actualPgVersion =
          }

      it "works with a non-scalar result" $
-        post "/rpc/get_projects_below?select=id,name"
+        request methodPost "/rpc/get_projects_below?select=id,name" [("Prefer", "params=multiple-objects")]
          [json|[
            {"id": 1},
-            {"id": 5}
-          ]|] `shouldRespondWith`
+            {"id": 5} ]|]
+          `shouldRespondWith`
          [json|
            [{"id":1,"name":"Windows 7"},
             {"id":2,"name":"Windows 10"},
@@ -469,6 +506,82 @@ spec actualPgVersion =
             {"id":4,"name":"OSX"}]
          |] { matchHeaders = [matchContentTypeJson] }

+    context "HTTP request env vars" $ do
+      it "custom header is set" $
+        request methodPost "/rpc/get_guc_value"
+                  [("Custom-Header", "test")]
+            [json| { "name": "request.header.custom-header" } |]
+            `shouldRespondWith`
+            [str|"test"|]
+            { matchStatus  = 200
+            , matchHeaders = [ matchContentTypeJson ]
+            }
+      it "standard header is set" $
+        request methodPost "/rpc/get_guc_value"
+                  [("Origin", "http://example.com")]
+            [json| { "name": "request.header.origin" } |]
+            `shouldRespondWith`
+            [str|"http://example.com"|]
+            { matchStatus  = 200
+            , matchHeaders = [ matchContentTypeJson ]
+            }
+      it "current role is available as GUC claim" $
+        request methodPost "/rpc/get_guc_value" []
+            [json| { "name": "request.jwt.claim.role" } |]
+            `shouldRespondWith`
+            [str|"postgrest_test_anonymous"|]
+            { matchStatus  = 200
+            , matchHeaders = [ matchContentTypeJson ]
+            }
+      it "single cookie ends up as claims" $
+        request methodPost "/rpc/get_guc_value" [("Cookie","acookie=cookievalue")]
+          [json| {"name":"request.cookie.acookie"} |]
+            `shouldRespondWith`
+            [str|"cookievalue"|]
+            { matchStatus = 200
+            , matchHeaders = []
+            }
+      it "multiple cookies ends up as claims" $
+        request methodPost "/rpc/get_guc_value" [("Cookie","acookie=cookievalue;secondcookie=anothervalue")]
+          [json| {"name":"request.cookie.secondcookie"} |]
+            `shouldRespondWith`
+            [str|"anothervalue"|]
+            { matchStatus = 200
+            , matchHeaders = []
+            }
+      it "app settings available" $
+        request methodPost "/rpc/get_guc_value" []
+          [json| { "name": "app.settings.app_host" } |]
+            `shouldRespondWith`
+            [str|"localhost"|]
+            { matchStatus  = 200
+            , matchHeaders = [ matchContentTypeJson ]
+            }
+      it "gets the Authorization value" $
+        request methodPost "/rpc/get_guc_value" [authHeaderJWT "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoicG9zdGdyZXN0X3Rlc3RfYXV0aG9yIn0.Xod-F15qsGL0WhdOCr2j3DdKuTw9QJERVgoFD3vGaWA"]
+          [json| {"name":"request.header.authorization"} |]
+            `shouldRespondWith`
+            [str|"Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoicG9zdGdyZXN0X3Rlc3RfYXV0aG9yIn0.Xod-F15qsGL0WhdOCr2j3DdKuTw9QJERVgoFD3vGaWA"|]
+            { matchStatus = 200
+            , matchHeaders = []
+            }
+      it "gets the http method" $
+        request methodPost "/rpc/get_guc_value" []
+          [json| {"name":"request.method"} |]
+            `shouldRespondWith`
+            [str|"POST"|]
+            { matchStatus = 200
+            , matchHeaders = []
+            }
+      it "gets the http path" $
+        request methodPost "/rpc/get_guc_value" []
+          [json| {"name":"request.path"} |]
+            `shouldRespondWith`
+            [str|"/rpc/get_guc_value"|]
+            { matchStatus = 200
+            , matchHeaders = []
+            }
+
    context "binary output" $ do
      context "Proc that returns scalar" $ do
        it "can query without selecting column" $
@@ -478,23 +591,6 @@ spec actualPgVersion =
            , matchHeaders = ["Content-Type" <:> "application/octet-stream; charset=utf-8"]
            }

-        it "can get raw output with Accept: text/html" $
-          request methodGet "/rpc/welcome.html" (acceptHdrs "text/html") ""
-            `shouldRespondWith`
-            [str|
-                |<html>
-                |  <head>
-                |    <title>PostgREST</title>
-                |  </head>
-                |  <body>
-                |    <h1>Welcome to PostgREST</h1>
-                |  </body>
-                |</html>
-                |]
-            { matchStatus = 200
-            , matchHeaders = ["Content-Type" <:> "text/html; charset=utf-8"]
-            }
-
        it "can get raw output with Accept: text/plain" $
          request methodGet "/rpc/welcome" (acceptHdrs "text/plain") ""
            `shouldRespondWith` "Welcome to PostgREST"
@@ -513,7 +609,7 @@ spec actualPgVersion =
        it "fails if a single column is not selected" $
          request methodPost "/rpc/ret_rows_with_base64_bin" (acceptHdrs "application/octet-stream") ""
            `shouldRespondWith`
-            [json| {"message":"application/octet-stream requested but a single column was not selected"} |]
+            [json| {"message":"application/octet-stream requested but more than one column was selected"} |]
            { matchStatus = 406
            , matchHeaders = [matchContentTypeJson]
            }
@@ -546,6 +642,10 @@ spec actualPgVersion =
        get "/rpc/get_tsearch?text_search_vector=not.fts(english).fun%7Crat" `shouldRespondWith`
          [json|[{"text_search_vector":"'amus':5 'fair':7 'impossibl':9 'peu':4"},{"text_search_vector":"'art':4 'spass':5 'unmog':7"}]|]
          { matchHeaders = [matchContentTypeJson] }
+        when (actualPgVersion >= pgVersion112) $
+            get "/rpc/get_tsearch?text_search_vector=wfts.impossible" `shouldRespondWith`
+                [json|[{"text_search_vector":"'fun':5 'imposs':9 'kind':3"}]|]
+                { matchHeaders = [matchContentTypeJson] }

    it "should work with an argument of custom type in public schema" $
        get "/rpc/test_arg?my_arg=something" `shouldRespondWith`
@@ -13,7 +13,7 @@ import Protolude  hiding (get)
 import SpecHelper


-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "Requesting singular json object" $ do
    let pgrstObj = "application/vnd.pgrst.object+json"
@@ -56,7 +56,7 @@ spec =
        _ <- post "/addresses" [json| { id: 98, address: "xxx" } |]
        _ <- post "/addresses" [json| { id: 99, address: "yyy" } |]
        p <- request methodPatch "/addresses?id=gt.0"
-                [("Prefer", "return=representation"), singular]
+                [singular]
                [json| { address: "zzz" } |]
        liftIO $ do
          simpleStatus p `shouldBe` notAcceptable406
@@ -65,7 +65,29 @@ spec =
        -- the rows should not be updated, either
        get "/addresses?id=eq.98" `shouldRespondWith` [str|[{"id":98,"address":"xxx"}]|]

+      it "raises an error for multiple rows with return=rep" $ do
+        _ <- post "/addresses" [json| { id: 100, address: "xxx" } |]
+        _ <- post "/addresses" [json| { id: 101, address: "yyy" } |]
+        p <- request methodPatch "/addresses?id=gt.0"
+                [("Prefer", "return=representation"), singular]
+                [json| { address: "zzz" } |]
+        liftIO $ do
+          simpleStatus p `shouldBe` notAcceptable406
+          isErrorFormat (simpleBody p) `shouldBe` True
+
+        -- the rows should not be updated, either
+        get "/addresses?id=eq.100" `shouldRespondWith` [str|[{"id":100,"address":"xxx"}]|]
+
      it "raises an error for zero rows" $
+        request methodPatch "/items?id=gt.0&id=lt.0"
+                [singular] [json|{"id":1}|]
+          `shouldRespondWith`
+                  [str|{"details":"Results contain 0 rows, application/vnd.pgrst.object+json requires 1 row","message":"JSON object requested, multiple (or no) rows returned"}|]
+                  { matchStatus  = 406
+                  , matchHeaders = ["Content-Type" <:> "application/vnd.pgrst.object+json; charset=utf-8"]
+                  }
+
+      it "raises an error for zero rows with return=rep" $
        request methodPatch "/items?id=gt.0&id=lt.0"
                [("Prefer", "return=representation"), singular] [json|{"id":1}|]
          `shouldRespondWith`
@@ -79,20 +101,20 @@ spec =
        p <- request methodPost
          "/addresses"
          [("Prefer", "return=representation"), singular]
-          [json| [ { id: 100, address: "xxx" } ] |]
-        liftIO $ simpleBody p `shouldBe` [str|{"id":100,"address":"xxx"}|]
+          [json| [ { id: 102, address: "xxx" } ] |]
+        liftIO $ simpleBody p `shouldBe` [str|{"id":102,"address":"xxx"}|]

      it "works for one row even with return=minimal" $ do
        request methodPost "/addresses"
          [("Prefer", "return=minimal"), singular]
-          [json| [ { id: 101, address: "xxx" } ] |]
+          [json| [ { id: 103, address: "xxx" } ] |]
          `shouldRespondWith` ""
          { matchStatus  = 201
          , matchHeaders = ["Content-Range" <:> "*/*"]
          }
        -- and the element should exist
-        get "/addresses?id=eq.101"
-          `shouldRespondWith` [str|[{"id":101,"address":"xxx"}]|]
+        get "/addresses?id=eq.103"
+          `shouldRespondWith` [str|[{"id":103,"address":"xxx"}]|]
          { matchStatus  = 200
          , matchHeaders = []
          }
@@ -100,23 +122,47 @@ spec =
      it "raises an error when attempting to create multiple entities" $ do
        p <- request methodPost
          "/addresses"
-          [("Prefer", "return=representation"), singular]
+          [singular]
          [json| [ { id: 200, address: "xxx" }, { id: 201, address: "yyy" } ] |]
        liftIO $ simpleStatus p `shouldBe` notAcceptable406

        -- the rows should not exist, either
        get "/addresses?id=eq.200" `shouldRespondWith` "[]"

-      it "return=minimal allows request to create multiple elements" $
+      it "raises an error when attempting to create multiple entities with return=rep" $ do
+        p <- request methodPost
+          "/addresses"
+          [("Prefer", "return=representation"), singular]
+          [json| [ { id: 202, address: "xxx" }, { id: 203, address: "yyy" } ] |]
+        liftIO $ simpleStatus p `shouldBe` notAcceptable406
+
+        -- the rows should not exist, either
+        get "/addresses?id=eq.202" `shouldRespondWith` "[]"
+
+      it "raises an error regardless of return=minimal" $ do
        request methodPost "/addresses"
-          [("Prefer", "return=minimal"), singular]
-          [json| [ { id: 200, address: "xxx" }, { id: 201, address: "yyy" } ] |]
-          `shouldRespondWith` ""
-          { matchStatus  = 201
-          , matchHeaders = ["Content-Range" <:> "*/*"]
-          }
+                [("Prefer", "return=minimal"), singular]
+                [json| [ { id: 204, address: "xxx" }, { id: 205, address: "yyy" } ] |]
+          `shouldRespondWith`
+                  [str|{"details":"Results contain 2 rows, application/vnd.pgrst.object+json requires 1 row","message":"JSON object requested, multiple (or no) rows returned"}|]
+                  { matchStatus  = 406
+                  , matchHeaders = ["Content-Type" <:> "application/vnd.pgrst.object+json; charset=utf-8"]
+                  }
+
+        -- the rows should not exist, either
+        get "/addresses?id=eq.204" `shouldRespondWith` "[]"

      it "raises an error when creating zero entities" $
+        request methodPost "/addresses"
+                [singular]
+                [json| [ ] |]
+          `shouldRespondWith`
+                  [str|{"details":"Results contain 0 rows, application/vnd.pgrst.object+json requires 1 row","message":"JSON object requested, multiple (or no) rows returned"}|]
+                  { matchStatus  = 406
+                  , matchHeaders = ["Content-Type" <:> "application/vnd.pgrst.object+json; charset=utf-8"]
+                  }
+
+      it "raises an error when creating zero entities with return=rep" $
        request methodPost "/addresses"
                [("Prefer", "return=representation"), singular]
                [json| [ ] |]
@@ -134,18 +180,39 @@ spec =
        liftIO $ simpleBody p `shouldBe` [str|{"id":11}|]

      it "raises an error when attempting to delete multiple entities" $ do
-        let firstItems = "/items?id=gt.0&id=lt.11"
+        let firstItems = "/items?id=gt.0&id=lt.6"
+        request methodDelete firstItems
+          [singular] ""
+          `shouldRespondWith` 406
+
+        get firstItems
+          `shouldRespondWith` [json| [{"id":1},{"id":2},{"id":3},{"id":4},{"id":5}] |]
+          { matchStatus  = 200
+          , matchHeaders = ["Content-Range" <:> "0-4/*"]
+          }
+
+      it "raises an error when attempting to delete multiple entities with return=rep" $ do
+        let firstItems = "/items?id=gt.5&id=lt.11"
        request methodDelete firstItems
          [("Prefer", "return=representation"), singular] ""
          `shouldRespondWith` 406

        get firstItems
-          `shouldRespondWith` [json| [{"id":1},{"id":2},{"id":3},{"id":4},{"id":5},{"id":6},{"id":7},{"id":8},{"id":9},{"id":10}] |]
+          `shouldRespondWith` [json| [{"id":6},{"id":7},{"id":8},{"id":9},{"id":10}] |]
          { matchStatus  = 200
-          , matchHeaders = ["Content-Range" <:> "0-9/*"]
+          , matchHeaders = ["Content-Range" <:> "0-4/*"]
          }

      it "raises an error when deleting zero entities" $
+        request methodDelete "/items?id=lt.0"
+                [singular] ""
+          `shouldRespondWith`
+                [str|{"details":"Results contain 0 rows, application/vnd.pgrst.object+json requires 1 row","message":"JSON object requested, multiple (or no) rows returned"}|]
+                { matchStatus  = 406
+                , matchHeaders = ["Content-Type" <:> "application/vnd.pgrst.object+json; charset=utf-8"]
+                }
+
+      it "raises an error when deleting zero entities with return=rep" $
        request methodDelete "/items?id=lt.0"
                [("Prefer", "return=representation"), singular] ""
          `shouldRespondWith`
@@ -17,12 +17,14 @@ import PostgREST.Config (docsVersion)
 import Protolude        hiding (get)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec = do

  describe "OpenAPI" $ do
-    it "root path returns a valid openapi spec" $
+    it "root path returns a valid openapi spec" $ do
      validateOpenApiResponse [("Accept", "application/openapi+json")]
+      request methodHead "/" (acceptHdrs "application/openapi+json") ""
+        `shouldRespondWith` "" { matchStatus  = 200 }

    it "should respond to openapi request on none root path with 415" $
      request methodGet "/items"
@@ -45,6 +47,7 @@ spec = do
            childGetSummary = r ^? method "get" . key "summary"
            childGetDescription = r ^? method "get" . key "description"
            getParameters = r ^? method "get" . key "parameters"
+            postParameters = r ^? method "post" . key "parameters"
            postResponse = r ^? method "post" . key "responses" . key "201" . key "description"
            patchResponse = r ^? method "patch" . key "responses" . key "204" . key "description"
            deleteResponse = r ^? method "delete" . key "responses" . key "204" . key "description"
@@ -79,6 +82,15 @@ spec = do
              ]
            |]

+          postParameters `shouldBe` Just
+            [aesonQQ|
+              [
+                { "$ref": "#/parameters/body.child_entities" },
+                { "$ref": "#/parameters/select" },
+                { "$ref": "#/parameters/preferReturn" }
+              ]
+            |]
+
          postResponse `shouldBe` Just "Created"

          patchResponse `shouldBe` Just "No Content"
@@ -125,7 +137,7 @@ spec = do
                    "type": "integer"
                  },
                  "name": {
-                    "description": "child_entities name comment",
+                    "description": "child_entities name comment. Can be longer than sixty-three characters long",
                    "format": "text",
                    "type": "string"
                  },
@@ -219,6 +231,23 @@ spec = do
              ]
            |]

+    describe "VIEW that has a source FK based on a UNIQUE key" $
+
+      it "includes fk description" $ do
+        r <- simpleBody <$> get "/"
+
+        let referralLink = r ^? key "definitions" . key "referrals" . key "properties" . key "link"
+
+        liftIO $
+          referralLink `shouldBe` Just
+            [aesonQQ|
+              {
+                "format": "integer",
+                "type": "integer",
+                "description": "Note:\nThis is a Foreign Key to `pages.link`.<fk table='pages' column='link'/>"
+              }
+            |]
+
    describe "PostgreSQL to Swagger Type Mapping" $ do

      it "character varying to string" $ do
@@ -1,7 +1,6 @@
 module Feature.UnicodeSpec where

-import Control.Monad (void)
-import Network.Wai   (Application)
+import Network.Wai (Application)

 import Test.Hspec
 import Test.Hspec.Wai
@@ -10,7 +9,7 @@ import Test.Hspec.Wai.JSON
 import Protolude  hiding (get)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "Reading and writing to unicode schema and table names" $
    it "Can read and write values" $ do
@@ -11,7 +11,7 @@ import Text.Heredoc
 import Protolude  hiding (get, put)
 import SpecHelper

-spec :: SpecWith Application
+spec :: SpecWith ((), Application)
 spec =
  describe "UPSERT" $ do
    context "with POST" $ do
@@ -49,6 +49,31 @@ spec =
            [json|[]|] `shouldRespondWith`
            [json|[]|] { matchStatus = 201 , matchHeaders = [matchContentTypeJson] }

+        it "INSERTs and UPDATEs rows on single unique key conflict" $
+          request methodPost "/single_unique?on_conflict=unique_key" [("Prefer", "return=representation"), ("Prefer", "resolution=merge-duplicates")]
+            [json| [
+              { "unique_key": 1, "value": "B" },
+              { "unique_key": 2, "value": "C" }
+            ]|] `shouldRespondWith` [json| [
+              { "unique_key": 1, "value": "B" },
+              { "unique_key": 2, "value": "C" }
+            ]|]
+            { matchStatus = 201
+            , matchHeaders = ["Preference-Applied" <:> "resolution=merge-duplicates", matchContentTypeJson]
+            }
+
+        it "INSERTs and UPDATEs rows on compound unique keys conflict" $
+          request methodPost "/compound_unique?on_conflict=key1,key2" [("Prefer", "return=representation"), ("Prefer", "resolution=merge-duplicates")]
+            [json| [
+              { "key1": 1, "key2": 1, "value": "B" },
+              { "key1": 1, "key2": 2, "value": "C" }
+            ]|] `shouldRespondWith` [json| [
+              { "key1": 1, "key2": 1, "value": "B" },
+              { "key1": 1, "key2": 2, "value": "C" }
+            ]|]
+            { matchStatus = 201
+            , matchHeaders = ["Preference-Applied" <:> "resolution=merge-duplicates", matchContentTypeJson]
+            }

      context "when Prefer: resolution=ignore-duplicates is specified" $ do
        it "INSERTs and ignores rows on pk conflict" $
@@ -75,6 +100,32 @@ spec =
            , matchHeaders = ["Preference-Applied" <:> "resolution=ignore-duplicates", matchContentTypeJson]
            }

+        it "INSERTs and ignores rows on single unique key conflict" $
+          request methodPost "/single_unique?on_conflict=unique_key" [("Prefer", "return=representation"), ("Prefer", "resolution=ignore-duplicates")]
+            [json| [
+              { "unique_key": 1, "value": "B" },
+              { "unique_key": 2, "value": "C" },
+              { "unique_key": 3, "value": "D" }
+            ]|] `shouldRespondWith` [json| [
+              { "unique_key": 3, "value": "D" }
+            ]|]
+            { matchStatus = 201
+            , matchHeaders = ["Preference-Applied" <:> "resolution=ignore-duplicates", matchContentTypeJson]
+            }
+
+        it "INSERTs and UPDATEs rows on compound unique keys conflict" $
+          request methodPost "/compound_unique?on_conflict=key1,key2" [("Prefer", "return=representation"), ("Prefer", "resolution=ignore-duplicates")]
+            [json| [
+              { "key1": 1, "key2": 1, "value": "B" },
+              { "key1": 1, "key2": 2, "value": "C" },
+              { "key1": 1, "key2": 3, "value": "D" }
+            ]|] `shouldRespondWith` [json| [
+              { "key1": 1, "key2": 3, "value": "D" }
+            ]|]
+            { matchStatus = 201
+            , matchHeaders = ["Preference-Applied" <:> "resolution=ignore-duplicates", matchContentTypeJson]
+            }
+
      it "succeeds if the table has only PK cols and no other cols" $ do
        request methodPost "/only_pk" [("Prefer", "return=representation"), ("Prefer", "resolution=ignore-duplicates")]
          [json|[ { "id": 1 }, { "id": 2 }, { "id": 3} ]|]
@@ -129,26 +180,6 @@ spec =
            [json|{"message":"Range header and limit/offset querystring parameters are not allowed for PUT"}|]
            { matchStatus = 400 , matchHeaders = [matchContentTypeJson] }

-        it "fails if the payload has more than one row" $
-          put "/tiobe_pls?name=eq.Go"
-            [str| [ { "name": "Go", "rank": 19 }, { "name": "Swift", "rank": 12 } ]|]
-            `shouldRespondWith`
-            [json|{"message":"PUT payload must contain a single row"}|]
-            { matchStatus = 400 , matchHeaders = [matchContentTypeJson] }
-
-        it "fails if not all columns are specified" $ do
-          put "/tiobe_pls?name=eq.Go"
-            [str| [ { "name": "Go" } ]|]
-            `shouldRespondWith`
-            [json|{"message":"You must specify all columns in the payload when using PUT"}|]
-            { matchStatus = 400 , matchHeaders = [matchContentTypeJson] }
-
-          put "/employees?first_name=eq.Susan&last_name=eq.Heidt"
-            [str| [ { "first_name": "Susan", "last_name": "Heidt", "salary": "48000" } ]|]
-            `shouldRespondWith`
-            [json|{"message":"You must specify all columns in the payload when using PUT"}|]
-            { matchStatus = 400 , matchHeaders = [matchContentTypeJson] }
-
        it "rejects every other filter than pk cols eq's" $ do
          put "/tiobe_pls?rank=eq.19"
            [str| [ { "name": "Go", "rank": 19 } ]|]
@@ -229,6 +260,14 @@ spec =
          put "/tiobe_pls?name=eq.Go" [str| [ { "name": "Go", "rank": 13 } ]|] `shouldRespondWith` 204
          get "/tiobe_pls?name=eq.Go" `shouldRespondWith` [json| [ { "name": "Go", "rank": 13 } ]|] { matchHeaders = [matchContentTypeJson] }

+        it "succeeds if the payload has more than one row, but it only puts the first element" $
+          request methodPut "/tiobe_pls?name=eq.Go"
+            [("Prefer", "return=representation"), ("Accept", "application/vnd.pgrst.object+json")]
+            [str| [ { "name": "Go", "rank": 19 }, { "name": "Swift", "rank": 12 } ] |]
+            `shouldRespondWith`
+            [json|{ "name": "Go", "rank": 19 }|]
+            { matchStatus = 200 , matchHeaders = [matchContentTypeSingular] }
+
        it "succeeds on table with composite pk" $ do
          get "/employees?first_name=eq.Susan&last_name=eq.Heidt"
            `shouldRespondWith`
@@ -6,16 +6,18 @@ import qualified Hasql.Transaction.Sessions as HT
 import Control.AutoUpdate (defaultUpdateSettings, mkAutoUpdate,
                           updateAction)
 import Data.Function      (id)
+import Data.List.NonEmpty (toList)
 import Data.Time.Clock    (getCurrentTime)

 import Data.IORef
 import Test.Hspec

 import PostgREST.App         (postgrest)
+import PostgREST.Config      (AppConfig (..))
 import PostgREST.DbStructure (getDbStructure, getPgVersion)
-import PostgREST.Types       (DbStructure (..), pgVersion95,
-                              pgVersion96)
-import Protolude
+import PostgREST.Types       (pgVersion95, pgVersion96)
+import Protolude             hiding (toList, toS)
+import Protolude.Conv        (toS)
 import SpecHelper

 import qualified Feature.AndOrParamsSpec
@@ -26,9 +28,12 @@ import qualified Feature.BinaryJwtSecretSpec
 import qualified Feature.ConcurrentSpec
 import qualified Feature.CorsSpec
 import qualified Feature.DeleteSpec
+import qualified Feature.EmbedDisambiguationSpec
 import qualified Feature.ExtraSearchPathSpec
+import qualified Feature.HtmlRawOutputSpec
 import qualified Feature.InsertSpec
 import qualified Feature.JsonOperatorSpec
+import qualified Feature.MultipleSchemaSpec
 import qualified Feature.NoJwtSpec
 import qualified Feature.NonexistentSchemaSpec
 import qualified Feature.PgVersion95Spec
@@ -37,6 +42,7 @@ import qualified Feature.ProxySpec
 import qualified Feature.QueryLimitedSpec
 import qualified Feature.QuerySpec
 import qualified Feature.RangeSpec
+import qualified Feature.RawOutputTypesSpec
 import qualified Feature.RootSpec
 import qualified Feature.RpcSpec
 import qualified Feature.SingularSpec
@@ -47,102 +53,136 @@ import qualified Feature.UpsertSpec

 main :: IO ()
 main = do
+  getTime <- mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
+
  testDbConn <- getEnvVarWithDefault "POSTGREST_TEST_CONNECTION" "postgres://postgrest_test@localhost/postgrest_test"
-  setupDb testDbConn

  pool <- P.acquire (3, 10, toS testDbConn)

-  result <- P.use pool $ do
-    ver <- getPgVersion
-    HT.transaction HT.ReadCommitted HT.Read $ getDbStructure "test" ver
+  actualPgVersion <- either (panic.show) id <$> P.use pool getPgVersion

-  let dbStructure = either (panic.show) id result
+  refDbStructure <- (newIORef . Just) =<< setupDbStructure pool (configSchemas $ testCfg testDbConn) actualPgVersion

-  getTime <- mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
+  let
+    -- For tests that run with the same refDbStructure
+    app cfg = return ((), postgrest (cfg testDbConn) refDbStructure pool getTime $ pure ())

-  refDbStructure <- newIORef $ Just dbStructure
+    -- For tests that run with a different DbStructure(depends on configSchemas)
+    appDbs cfg = do
+      dbs <- (newIORef . Just) =<< setupDbStructure pool (configSchemas $ cfg testDbConn) actualPgVersion
+      return ((), postgrest (cfg testDbConn) dbs pool getTime $ pure ())

-  let withApp              = return $ postgrest (testCfg testDbConn)                  refDbStructure pool getTime $ pure ()
-      ltdApp               = return $ postgrest (testLtdRowsCfg testDbConn)           refDbStructure pool getTime $ pure ()
-      unicodeApp           = return $ postgrest (testUnicodeCfg testDbConn)           refDbStructure pool getTime $ pure ()
-      proxyApp             = return $ postgrest (testProxyCfg testDbConn)             refDbStructure pool getTime $ pure ()
-      noJwtApp             = return $ postgrest (testCfgNoJWT testDbConn)             refDbStructure pool getTime $ pure ()
-      binaryJwtApp         = return $ postgrest (testCfgBinaryJWT testDbConn)         refDbStructure pool getTime $ pure ()
-      audJwtApp            = return $ postgrest (testCfgAudienceJWT testDbConn)       refDbStructure pool getTime $ pure ()
-      asymJwkApp           = return $ postgrest (testCfgAsymJWK testDbConn)           refDbStructure pool getTime $ pure ()
-      asymJwkSetApp        = return $ postgrest (testCfgAsymJWKSet testDbConn)        refDbStructure pool getTime $ pure ()
-      nonexistentSchemaApp = return $ postgrest (testNonexistentSchemaCfg testDbConn) refDbStructure pool getTime $ pure ()
-      extraSearchPathApp   = return $ postgrest (testCfgExtraSearchPath testDbConn)   refDbStructure pool getTime $ pure ()
-      rootSpecApp          = return $ postgrest (testCfgRootSpec testDbConn)          refDbStructure pool getTime $ pure ()
+  let withApp              = app testCfg
+      maxRowsApp           = app testMaxRowsCfg
+      proxyApp             = app testProxyCfg
+      noJwtApp             = app testCfgNoJWT
+      binaryJwtApp         = app testCfgBinaryJWT
+      audJwtApp            = app testCfgAudienceJWT
+      asymJwkApp           = app testCfgAsymJWK
+      asymJwkSetApp        = app testCfgAsymJWKSet
+      extraSearchPathApp   = app testCfgExtraSearchPath
+      rootSpecApp          = app testCfgRootSpec
+      htmlRawOutputApp     = app testCfgHtmlRawOutput
+      responseHeadersApp   = app testCfgResponseHeaders

-  let reset :: IO ()
+      unicodeApp           = appDbs testUnicodeCfg
+      nonexistentSchemaApp = appDbs testNonexistentSchemaCfg
+      multipleSchemaApp    = appDbs testMultipleSchemaCfg
+
+  let reset, analyze :: IO ()
      reset = resetDb testDbConn
+      analyze = do
+        analyzeTable testDbConn "items"
+        analyzeTable testDbConn "child_entities"

-      actualPgVersion = pgVersion dbStructure
      extraSpecs =
        [("Feature.UpsertSpec", Feature.UpsertSpec.spec) | actualPgVersion >= pgVersion95] ++
-        [("Feature.PgVersion95Spec", Feature.PgVersion95Spec.spec) | actualPgVersion >= pgVersion95] ++
-        [("Feature.PgVersion96Spec", Feature.PgVersion96Spec.spec) | actualPgVersion >= pgVersion96]
+        [("Feature.PgVersion95Spec", Feature.PgVersion95Spec.spec) | actualPgVersion >= pgVersion95]

      specs = uncurry describe <$> [
-          ("Feature.AuthSpec"               , Feature.AuthSpec.spec actualPgVersion)
-        , ("Feature.ConcurrentSpec"         , Feature.ConcurrentSpec.spec)
-        , ("Feature.CorsSpec"               , Feature.CorsSpec.spec)
-        , ("Feature.DeleteSpec"             , Feature.DeleteSpec.spec)
-        , ("Feature.InsertSpec"             , Feature.InsertSpec.spec actualPgVersion)
-        , ("Feature.JsonOperatorSpec"       , Feature.JsonOperatorSpec.spec actualPgVersion)
-        , ("Feature.QuerySpec"              , Feature.QuerySpec.spec)
-        , ("Feature.RpcSpec"                , Feature.RpcSpec.spec actualPgVersion)
-        , ("Feature.RangeSpec"              , Feature.RangeSpec.spec)
-        , ("Feature.SingularSpec"           , Feature.SingularSpec.spec)
-        , ("Feature.StructureSpec"          , Feature.StructureSpec.spec)
-        , ("Feature.AndOrParamsSpec"        , Feature.AndOrParamsSpec.spec)
+          ("Feature.AuthSpec"                , Feature.AuthSpec.spec actualPgVersion)
+        , ("Feature.RawOutputTypesSpec"      , Feature.RawOutputTypesSpec.spec)
+        , ("Feature.ConcurrentSpec"          , Feature.ConcurrentSpec.spec)
+        , ("Feature.CorsSpec"                , Feature.CorsSpec.spec)
+        , ("Feature.JsonOperatorSpec"        , Feature.JsonOperatorSpec.spec actualPgVersion)
+        , ("Feature.QuerySpec"               , Feature.QuerySpec.spec actualPgVersion)
+        , ("Feature.EmbedDisambiguationSpec" , Feature.EmbedDisambiguationSpec.spec)
+        , ("Feature.RpcSpec"                 , Feature.RpcSpec.spec actualPgVersion)
+        , ("Feature.StructureSpec"           , Feature.StructureSpec.spec)
+        , ("Feature.AndOrParamsSpec"         , Feature.AndOrParamsSpec.spec actualPgVersion)
        ] ++ extraSpecs

+      mutSpecs = uncurry describe <$> [
+          ("Feature.DeleteSpec"             , Feature.DeleteSpec.spec)
+        , ("Feature.InsertSpec"             , Feature.InsertSpec.spec actualPgVersion)
+        , ("Feature.SingularSpec"           , Feature.SingularSpec.spec)
+        ]
+
  hspec $ do
-    mapM_ (beforeAll_ reset . before withApp) specs
+    -- Only certain Specs need a database reset, this should be used with care as it slows down the whole test suite.
+    mapM_ (afterAll_ reset . before withApp) mutSpecs
+
+    mapM_ (before withApp) specs
+
+    -- we analyze to get accurate results from EXPLAIN
+    beforeAll_ analyze . before withApp $
+      describe "Feature.RangeSpec" Feature.RangeSpec.spec
+
+    -- this test runs with a raw-output-media-types set to text/html
+    before htmlRawOutputApp $
+      describe "Feature.HtmlRawOutputSpec" Feature.HtmlRawOutputSpec.spec

    -- this test runs with a different server flag
-    beforeAll_ reset . before ltdApp $
+    before maxRowsApp $
      describe "Feature.QueryLimitedSpec" Feature.QueryLimitedSpec.spec

    -- this test runs with a different schema
-    beforeAll_ reset . before unicodeApp $
+    before unicodeApp $
      describe "Feature.UnicodeSpec" Feature.UnicodeSpec.spec

    -- this test runs with a proxy
-    beforeAll_ reset . before proxyApp $
+    before proxyApp $
      describe "Feature.ProxySpec" Feature.ProxySpec.spec

    -- this test runs without a JWT secret
-    beforeAll_ reset . before noJwtApp $
+    before noJwtApp $
      describe "Feature.NoJwtSpec" Feature.NoJwtSpec.spec

    -- this test runs with a binary JWT secret
-    beforeAll_ reset . before binaryJwtApp $
+    before binaryJwtApp $
      describe "Feature.BinaryJwtSecretSpec" Feature.BinaryJwtSecretSpec.spec

    -- this test runs with a binary JWT secret and an audience claim
-    beforeAll_ reset . before audJwtApp $
+    before audJwtApp $
      describe "Feature.AudienceJwtSecretSpec" Feature.AudienceJwtSecretSpec.spec

    -- this test runs with asymmetric JWK
-    beforeAll_ reset . before asymJwkApp $
+    before asymJwkApp $
      describe "Feature.AsymmetricJwtSpec" Feature.AsymmetricJwtSpec.spec

    -- this test runs with asymmetric JWKSet
-    beforeAll_ reset . before asymJwkSetApp $
+    before asymJwkSetApp $
      describe "Feature.AsymmetricJwtSpec" Feature.AsymmetricJwtSpec.spec

    -- this test runs with a nonexistent db-schema
-    beforeAll_ reset . before nonexistentSchemaApp $
+    before nonexistentSchemaApp $
      describe "Feature.NonexistentSchemaSpec" Feature.NonexistentSchemaSpec.spec

    -- this test runs with an extra search path
-    beforeAll_ reset . before extraSearchPathApp $
+    before extraSearchPathApp $
      describe "Feature.ExtraSearchPathSpec" Feature.ExtraSearchPathSpec.spec

    -- this test runs with a root spec function override
-    when (actualPgVersion >= pgVersion96) $
-      beforeAll_ reset . before rootSpecApp $
+    when (actualPgVersion >= pgVersion96) $ do
+      before rootSpecApp $
        describe "Feature.RootSpec" Feature.RootSpec.spec
+      before responseHeadersApp $
+        describe "Feature.PgVersion96Spec" Feature.PgVersion96Spec.spec
+
+    -- this test runs with multiple schemas
+    before multipleSchemaApp $
+      describe "Feature.MultipleSchemaSpec" $ Feature.MultipleSchemaSpec.spec actualPgVersion
+
+  where
+    setupDbStructure pool schemas ver =
+      either (panic.show) id <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ getDbStructure (toList schemas) ver)
@@ -0,0 +1,76 @@
+module Main where
+
+import           Control.Lens               ((^?))
+import qualified Data.Aeson.Lens            as L
+import qualified Hasql.Decoders             as HD
+import qualified Hasql.Encoders             as HE
+import qualified Hasql.Pool                 as P
+import qualified Hasql.Statement            as H
+import qualified Hasql.Transaction          as HT
+import qualified Hasql.Transaction.Sessions as HT
+import           Text.Heredoc
+
+import Protolude      hiding (get, toS)
+import Protolude.Conv (toS)
+
+import PostgREST.QueryBuilder (requestToCallProcQuery)
+import PostgREST.Types
+
+import SpecHelper (getEnvVarWithDefault)
+
+import Test.Hspec
+
+main :: IO ()
+main = do
+  testDbConn <- getEnvVarWithDefault "POSTGREST_TEST_CONNECTION" "postgres://postgrest_test@localhost/postgrest_test"
+  pool <- P.acquire (3, 10, toS testDbConn)
+
+  hspec $ describe "QueryCost" $
+    context "call proc query" $ do
+      it "should not exceed cost when calling setof composite proc" $ do
+        cost <- exec pool [str| {"id": 3} |] $
+          requestToCallProcQuery (QualifiedIdentifier "test" "get_projects_below") [PgArg "id" "int" True] False Nothing []
+        liftIO $
+          cost `shouldSatisfy` (< Just 40)
+
+      it "should not exceed cost when calling setof composite proc with empty params" $ do
+        cost <- exec pool mempty $
+          requestToCallProcQuery (QualifiedIdentifier "test" "getallprojects") [] False Nothing []
+        liftIO $
+          cost `shouldSatisfy` (< Just 30)
+
+      it "should not exceed cost when calling scalar proc" $ do
+        cost <- exec pool [str| {"a": 3, "b": 4} |] $
+          requestToCallProcQuery (QualifiedIdentifier "test" "add_them") [PgArg "a" "int" True, PgArg "b" "int" True] True Nothing []
+        liftIO $
+          cost `shouldSatisfy` (< Just 10)
+
+      context "params=multiple-objects" $ do
+        it "should not exceed cost when calling setof composite proc" $ do
+          cost <- exec pool [str| [{"id": 1}, {"id": 4}] |] $
+            requestToCallProcQuery (QualifiedIdentifier "test" "get_projects_below") [PgArg "id" "int" True] False (Just MultipleObjects) []
+          liftIO $ do
+            cost `shouldSatisfy` (> Just 2000)
+            cost `shouldSatisfy` (< Just 2100)
+
+        it "should not exceed cost when calling scalar proc" $ do
+          cost <- exec pool [str| [{"a": 3, "b": 4}, {"a": 1, "b": 2}, {"a": 8, "b": 7}] |] $
+            requestToCallProcQuery (QualifiedIdentifier "test" "add_them") [PgArg "a" "int" True, PgArg "b" "int" True] True Nothing []
+          liftIO $
+            cost `shouldSatisfy` (< Just 10)
+
+
+exec :: P.Pool -> ByteString -> SqlQuery -> IO (Maybe Int64)
+exec pool input query =
+  join . rightToMaybe <$>
+  P.use pool (HT.transaction HT.ReadCommitted HT.Read $ HT.statement input $ explainCost query)
+
+explainCost :: SqlQuery -> H.Statement ByteString (Maybe Int64)
+explainCost query =
+  H.Statement (encodeUtf8 sql) (HE.param $ HE.nonNullable HE.unknown) decodeExplain False
+ where
+   sql = "EXPLAIN (FORMAT JSON) " <> query
+   decodeExplain :: HD.Result (Maybe Int64)
+   decodeExplain =
+     let row = HD.singleRow $ HD.column $ HD.nonNullable HD.bytea in
+     (^? L.nth 0 . L.key "Plan" .  L.key "Total Cost" . L._Integral) <$> row
@@ -7,10 +7,10 @@ import qualified Data.Map.Strict        as M
 import qualified Data.Set               as S
 import qualified System.IO.Error        as E

-import Control.Monad        (void)
 import Data.Aeson           (Value (..), decode, encode)
 import Data.CaseInsensitive (CI (..))
 import Data.List            (lookup)
+import Data.List.NonEmpty   (fromList)
 import Network.Wai.Test     (SResponse (simpleBody, simpleHeaders, simpleStatus))
 import System.Environment   (getEnv)
 import System.Process       (readProcess)
@@ -23,8 +23,9 @@ import Test.Hspec.Wai
 import Text.Heredoc

 import PostgREST.Config (AppConfig (..))
-import PostgREST.Types  (JSPathExp (..), QualifiedIdentifier (..))
-import Protolude
+import PostgREST.Types  (JSPathExp (..))
+import Protolude        hiding (toS)
+import Protolude.Conv   (toS)

 matchContentTypeJson :: MatchHeader
 matchContentTypeJson = "Content-Type" <:> "application/json; charset=utf-8"
@@ -32,7 +33,7 @@ matchContentTypeJson = "Content-Type" <:> "application/json; charset=utf-8"
 matchContentTypeSingular :: MatchHeader
 matchContentTypeSingular = "Content-Type" <:> "application/vnd.pgrst.object+json; charset=utf-8"

-validateOpenApiResponse :: [Header] -> WaiSession ()
+validateOpenApiResponse :: [Header] -> WaiSession () ()
 validateOpenApiResponse headers = do
  r <- request methodGet "/" headers ""
  liftIO $
@@ -63,9 +64,11 @@ getEnvVarWithDefault var def = toS <$>

 _baseCfg :: AppConfig
 _baseCfg =  -- Connection Settings
-  AppConfig mempty "postgrest_test_anonymous" Nothing "test" "localhost" 3000
+  AppConfig mempty "postgrest_test_anonymous" Nothing (fromList ["test"]) "localhost" 3000
            -- No user configured Unix Socket
            Nothing
+            -- No user configured Unix Socket file mode (defaults to 660)
+            (Right 432)
            -- Jwt settings
            (Just $ encodeUtf8 "reallyreallyreallyreallyverysafe") False Nothing
            -- Connection Modifiers
@@ -81,6 +84,8 @@ _baseCfg =  -- Connection Settings
            []
            -- No root spec override
            Nothing
+            -- Raw output media types
+            []

 testCfg :: Text -> AppConfig
 testCfg testDbConn = _baseCfg { configDatabase = testDbConn }
@@ -89,13 +94,13 @@ testCfgNoJWT :: Text -> AppConfig
 testCfgNoJWT testDbConn = (testCfg testDbConn) { configJwtSecret = Nothing }

 testUnicodeCfg :: Text -> AppConfig
-testUnicodeCfg testDbConn = (testCfg testDbConn) { configSchema = "تست" }
+testUnicodeCfg testDbConn = (testCfg testDbConn) { configSchemas = fromList ["تست"] }

-testLtdRowsCfg :: Text -> AppConfig
-testLtdRowsCfg testDbConn = (testCfg testDbConn) { configMaxRows = Just 2 }
+testMaxRowsCfg :: Text -> AppConfig
+testMaxRowsCfg testDbConn = (testCfg testDbConn) { configMaxRows = Just 2 }

 testProxyCfg :: Text -> AppConfig
-testProxyCfg testDbConn = (testCfg testDbConn) { configProxyUri = Just "https://postgrest.com/openapi.json" }
+testProxyCfg testDbConn = (testCfg testDbConn) { configOpenAPIProxyUri = Just "https://postgrest.com/openapi.json" }

 testCfgBinaryJWT :: Text -> AppConfig
 testCfgBinaryJWT testDbConn = (testCfg testDbConn) {
@@ -123,30 +128,33 @@ testCfgAsymJWKSet testDbConn = (testCfg testDbConn) {
  }

 testNonexistentSchemaCfg :: Text -> AppConfig
-testNonexistentSchemaCfg testDbConn = (testCfg testDbConn) { configSchema = "nonexistent" }
+testNonexistentSchemaCfg testDbConn = (testCfg testDbConn) { configSchemas = fromList ["nonexistent"] }

 testCfgExtraSearchPath :: Text -> AppConfig
 testCfgExtraSearchPath testDbConn = (testCfg testDbConn) { configExtraSearchPath = ["public", "extensions"] }

 testCfgRootSpec :: Text -> AppConfig
-testCfgRootSpec testDbConn = (testCfg testDbConn) { configRootSpec = Just $ QualifiedIdentifier "test" "root"}
+testCfgRootSpec testDbConn = (testCfg testDbConn) { configRootSpec = Just "root"}

-setupDb :: Text -> IO ()
-setupDb dbConn = do
-  loadFixture dbConn "database"
-  loadFixture dbConn "roles"
-  loadFixture dbConn "schema"
-  loadFixture dbConn "jwt"
-  loadFixture dbConn "jsonschema"
-  loadFixture dbConn "privileges"
-  resetDb dbConn
+testCfgHtmlRawOutput :: Text -> AppConfig
+testCfgHtmlRawOutput testDbConn = (testCfg testDbConn) { configRawMediaTypes = ["text/html"] }
+
+testCfgResponseHeaders :: Text -> AppConfig
+testCfgResponseHeaders testDbConn = (testCfg testDbConn) { configReqCheck = Just "custom_headers" }
+
+testMultipleSchemaCfg :: Text -> AppConfig
+testMultipleSchemaCfg testDbConn = (testCfg testDbConn) { configSchemas = fromList ["v1", "v2"] }

 resetDb :: Text -> IO ()
 resetDb dbConn = loadFixture dbConn "data"

+analyzeTable :: Text -> Text -> IO ()
+analyzeTable dbConn tableName =
+  void $ readProcess "psql" ["--set", "ON_ERROR_STOP=1", toS dbConn, "-a", "-c", toS $ "ANALYZE test.\"" <> tableName <> "\""] []
+
 loadFixture :: Text -> FilePath -> IO()
 loadFixture dbConn name =
-  void $ readProcess "psql" ["--set", "ON_ERROR_STOP=1", toS dbConn, "-a", "-f", "test/fixtures/" ++ name ++ ".sql"] []
+  void $ readProcess "psql" ["--set", "ON_ERROR_STOP=1", toS dbConn, "-q", "-f", "test/fixtures/" ++ name ++ ".sql"] []

 rangeHdrs :: ByteRange -> [Header]
 rangeHdrs r = [rangeUnit, (hRange, renderByteRange r)]
@@ -164,6 +172,12 @@ matchHeader :: CI BS.ByteString -> BS.ByteString -> [Header] -> Bool
 matchHeader name valRegex headers =
  maybe False (=~ valRegex) $ lookup name headers

+noBlankHeader :: [Header] -> Bool
+noBlankHeader = notElem mempty
+
+noProfileHeader :: [Header] -> Bool
+noProfileHeader headers = isNothing $ find ((== "Content-Profile") . fst) headers
+
 authHeaderBasic :: BS.ByteString -> BS.ByteString -> Header
 authHeaderBasic u p =
  (hAuthorization, "Basic " <> (toS . B64.encode . toS $ u <> ":" <> p))
@@ -55,6 +55,8 @@ ALTER DATABASE $DB SET LC_MESSAGES = 'POSIX';
 ALTER DATABASE $DB SET LC_MONETARY = 'POSIX';
 ALTER DATABASE $DB SET LC_NUMERIC = 'POSIX';
 ALTER DATABASE $DB SET LC_TIME = 'POSIX';
+
+\i $BASEPATH/fixtures/load.sql
 EOF

 #Remove database path from the connection uri--prevents setting up the new database name with PGDATABASE
@@ -0,0 +1,30 @@
+version: "3.6"
+
+services:
+  test:
+    build:
+      context: .
+      dockerfile: Dockerfile.test
+    depends_on:
+      - postgres
+    working_dir: /root/postgrest
+    volumes:
+      - ../:/root/postgrest
+      - stack-linux:/root/.stack
+      - stack-work:/root/postgrest/.stack-work
+    command: bash -c "POSTGREST_TEST_CONNECTION=$$(test/create_test_db 'postgres://postgres:postgres@postgres' test_db) stack test"
+
+  postgres:
+    image: postgres:12.2
+    environment:
+      POSTGRES_PASSWORD: postgres
+    volumes:
+      - postgres:/var/lib/postgresql/data
+
+volumes:
+  postgres:
+    driver_opts:
+      type: tmpfs
+      device: tmpfs
+  stack-linux:
+  stack-work:
@@ -207,6 +207,35 @@ INSERT INTO items VALUES (15);
 SELECT pg_catalog.setval('items_id_seq', 15, true);


+--
+-- Data for Name: items2; Type: TABLE DATA; Schema: test; Owner: -
+--
+
+TRUNCATE TABLE items2 CASCADE;
+INSERT INTO items2 VALUES (1);
+INSERT INTO items2 VALUES (2);
+INSERT INTO items2 VALUES (3);
+INSERT INTO items2 VALUES (4);
+INSERT INTO items2 VALUES (5);
+INSERT INTO items2 VALUES (6);
+INSERT INTO items2 VALUES (7);
+INSERT INTO items2 VALUES (8);
+INSERT INTO items2 VALUES (9);
+INSERT INTO items2 VALUES (10);
+INSERT INTO items2 VALUES (11);
+INSERT INTO items2 VALUES (12);
+INSERT INTO items2 VALUES (13);
+INSERT INTO items2 VALUES (14);
+INSERT INTO items2 VALUES (15);
+
+
+--
+-- Name: items_id_seq; Type: SEQUENCE SET; Schema: test; Owner: -
+--
+
+SELECT pg_catalog.setval('items2_id_seq', 15, true);
+
+
 --
 -- Data for Name: json; Type: TABLE DATA; Schema: test; Owner: -
 --
@@ -344,6 +373,12 @@ INSERT INTO employees VALUES
 TRUNCATE TABLE tiobe_pls CASCADE;
 INSERT INTO tiobe_pls VALUES ('Java', 1), ('C', 2), ('Python', 4);

+TRUNCATE TABLE single_unique CASCADE;
+INSERT INTO single_unique (unique_key, value) VALUES (1, 'A');
+
+TRUNCATE TABLE compound_unique CASCADE;
+INSERT INTO compound_unique (key1, key2, value) VALUES (1, 1, 'A');
+
 TRUNCATE TABLE only_pk CASCADE;
 INSERT INTO only_pk VALUES (1), (2);

@@ -499,3 +534,79 @@ COPY pgrst_reserved_chars ("*id*", ":arr->ow::cast", "(inside,parens)", "a.dotte
 2 | arrow-2 | parens-2 | dotted-2 | space-2
 3 | arrow-3 | parens-3 | dotted-3 | space-3
 \.
+
+TRUNCATE TABLE web_content CASCADE;
+INSERT INTO web_content VALUES (5, 'wat', null);
+INSERT INTO web_content VALUES (0, 'tardis', 5);
+INSERT INTO web_content VALUES (1, 'fezz', 0);
+INSERT INTO web_content VALUES (2, 'foo', 0);
+INSERT INTO web_content VALUES (3, 'bar', 0);
+INSERT INTO web_content VALUES (4, 'wut', 1);
+
+TRUNCATE TABLE app_users CASCADE;
+INSERT INTO app_users (id, email, "password") VALUES (1, 'test@123.com','pass');
+INSERT INTO app_users (id, email, "password") VALUES (2, 'abc@123.com','pass');
+INSERT INTO app_users (id, email, "password") VALUES (3, 'def@123.com','pass');
+
+TRUNCATE TABLE private.pages CASCADE;
+INSERT INTO private.pages VALUES (1, 'http://postgrest.org/en/v6.0/api.html');
+INSERT INTO private.pages VALUES (2, 'http://postgrest.org/en/v6.0/admin.html');
+
+TRUNCATE TABLE private.referrals CASCADE;
+INSERT INTO private.referrals VALUES ('github.com', 1);
+INSERT INTO private.referrals VALUES ('hub.docker.com', 2);
+
+TRUNCATE TABLE big_projects CASCADE;
+INSERT INTO big_projects (big_project_id, name)
+VALUES (1, 'big project 1'),
+       (2, 'big project 2');
+
+TRUNCATE TABLE sites CASCADE;
+INSERT INTO sites (site_id, name, main_project_id)
+VALUES (1, 'site 1', 1),
+       (2, 'site 2', null),
+       (3, 'site 3', 2),
+       (4, 'site 4', null);
+
+TRUNCATE TABLE jobs CASCADE;
+INSERT INTO jobs (job_id, name, site_id, big_project_id)
+VALUES ('bc5d5362-b881-438f-b9f5-7417e08704ed', 'job 1-1', 1, 1),
+       ('3bd52697-033b-4edd-8a28-46a9c04b7c1e', 'job 2-1', 2, 1),
+       ('e6e67e4e-19b1-11e9-ab14-d663bd873d93', 'job 2-2', 2, 2);
+
+TRUNCATE TABLE departments CASCADE;
+TRUNCATE TABLE agents CASCADE;
+INSERT INTO agents (id, name)
+VALUES (1, 'agent 1'),
+       (2, 'agent 2'),
+       (3, 'agent 3'),
+       (4, 'agent 4');
+
+INSERT INTO departments (id, name, head_id)
+VALUES (1, 'dep 1', 1),
+       (2, 'dep 3', 3);
+
+UPDATE agents SET department_id = 1 WHERE id in (1, 2);
+UPDATE agents SET department_id = 2 WHERE id in (3, 4);
+
+TRUNCATE TABLE schedules CASCADE;
+INSERT INTO schedules VALUES(1, 'morning', '06:00:00', '11:59:00');
+INSERT INTO schedules VALUES(2, 'afternoon', '12:00:00', '17:59:00');
+INSERT INTO schedules VALUES(3, 'night', '18:00:00', '23:59:00');
+INSERT INTO schedules VALUES(4, 'early morning', '00:00:00', '05:59:00');
+
+TRUNCATE TABLE activities CASCADE;
+INSERT INTO activities(id, schedule_id, car_id)    VALUES(1, 1, 'CAR-349');
+INSERT INTO activities(id, schedule_id, camera_id) VALUES(2, 3, 'CAM-123');
+
+TRUNCATE TABLE unit_workdays CASCADE;
+INSERT INTO unit_workdays VALUES(1, '2019-12-02', 1, 1, 2, 3);
+
+TRUNCATE TABLE v1.parents CASCADE;
+INSERT INTO v1.parents VALUES(1, 'parent v1-1'), (2, 'parent v1-2');
+
+TRUNCATE TABLE v2.parents CASCADE;
+INSERT INTO v2.parents VALUES(3, 'parent v2-3'), (4, 'parent v2-4');
+
+TRUNCATE TABLE v2.another_table CASCADE;
+INSERT INTO v2.another_table VALUES(5, 'value 5'), (6, 'value 6');
@@ -1,3 +1,3 @@
 set client_min_messages to warning;
-DROP SCHEMA IF EXISTS test, private, postgrest, jwt, public, تست, extensions CASCADE;
+DROP SCHEMA IF EXISTS test, private, postgrest, jwt, public, تست, extensions, v1, v2 CASCADE;
 DROP TYPE IF EXISTS jwt_token CASCADE;
@@ -20,7 +20,7 @@ HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
 MODIFICATIONS.
 */

-CREATE OR REPLACE FUNCTION _validate_json_schema_type(type text, data jsonb) RETURNS boolean AS $f$
+CREATE OR REPLACE FUNCTION public._validate_json_schema_type(type text, data jsonb) RETURNS boolean AS $f$
 BEGIN
  IF type = 'integer' THEN
    IF jsonb_typeof(data) != 'number' THEN
--- a/Show More
+++ b/Show More