Merge pull request #276 from ruslantalpa/master

Support for &select=col1,col2,col3 as suggested in issue #227

src/PostgREST/App.hs

@@ -64,7 +64,7 @@ app conf reqBody req =
       else do
         let qt = qualify table
             from = fromMaybe 0 $ rangeOffset <$> range
-            select = B.Stmt "select " V.empty True <>
+            query = B.Stmt "select " V.empty True <>
                   parentheticT (
                     whereT qt qq $ countRows qt
                   ) <> commaq <> (
@@ -72,9 +72,9 @@ app conf reqBody req =
                   . limitT range
                   . orderT (orderParse qq)
                   . whereT qt qq
-                  $ selectStar qt
+                  $ select qt qq
                 )
-        row <- H.maybeEx select
+        row <- H.maybeEx query
         let (tableTotal, queryTotal, body) =
               fromMaybe (0, 0, Just "" :: Maybe Text) row
             to = from+queryTotal-1

src/PostgREST/PgQuery.hs

@@ -58,7 +58,7 @@ whereT table params q =
    then q
    else q <> B.Stmt " where " empty True <> conjunction
  where
-   cols = [ col | col <- params, fst col `notElem` ["order"] ]
+   cols = [ col | col <- params, fst col `notElem` ["order","select"] ]
    wherePredTable = wherePred table
    conjunction = mconcat $ L.intersperse andq (map wherePredTable cols)
 
@@ -129,6 +129,29 @@ asJsonRow s = s { B.stmtTemplate = "row_to_json(t) from (" <> B.stmtTemplate s <
 selectStar :: QualifiedIdentifier -> PStmt
 selectStar t = B.Stmt ("select * from " <> fromQi t) empty True
 
+select :: QualifiedIdentifier -> Net.Query -> PStmt
+select table params =
+ if L.null cols
+   then selectStar table
+   else B.Stmt "select " empty True <> conjunction <> B.Stmt (" from " <> fromQi table ) empty True
+ where
+   selectTermTable = selectTerm table
+   conjunction = mconcat $ L.intersperse commaq (map selectTermTable cols)
+   columnsParam = fromMaybe "" $ join (lookup "select" params)
+   cols = filter ((>0) . T.length) $ map T.strip $ T.split (==',') $ cs columnsParam
+
+selectTerm :: QualifiedIdentifier -> T.Text -> PStmt
+selectTerm table col =
+    case T.splitOn "::" col of
+        [colName,castTo] -> B.Stmt ("CAST (" <> pgFmtJsonbPath table (cs colName) <> " AS " <> castToSafe <> " )" <> asT (jsonbPath colName)) empty True
+            where castToSafe = T.filter ( `elem` ['a'..'z'] ) castTo
+        _-> B.Stmt (pgFmtJsonbPath table (cs col) <> asT (jsonbPath col)) empty True
+    where
+        jsonbPath :: T.Text -> Maybe JsonbPath
+        jsonbPath c = parseJsonbPath $ cs c
+        asT (Just (DoubleArrow _ (KeyIdentifier key))) = " AS " <> pgFmtIdent key
+        asT _ = ""
+
 returningStarT :: StatementT
 returningStarT s = s { B.stmtTemplate = B.stmtTemplate s <> " RETURNING *" }
 

test/Feature/QuerySpec.hs

@@ -11,13 +11,14 @@ import SpecHelper
 spec :: Spec
 spec =
   beforeAll (clearTable "items" >> createItems 15)
+   . beforeAll (clearTable "complex_items" >> createComplexItems)
    . beforeAll (clearTable "nullable_integer" >> createNullInteger)
    . beforeAll (
        clearTable "no_pk" >>
        createNulls 2 >>
        createLikableStrings >>
        createJsonData)
-   . afterAll_ (clearTable "items" >> clearTable "no_pk" >> clearTable "simple_pk")
+   . afterAll_ (clearTable "items" >> clearTable "complex_items" >> clearTable "no_pk" >> clearTable "simple_pk")
    . around withApp $ do
 
   describe "Querying a table with a column called count" $
@@ -129,6 +130,55 @@ spec =
       get "/items?always_true=eq.true" `shouldRespondWith`
         [json| [{"id":1},{"id":2},{"id":3},{"id":4},{"id":5},{"id":6},{"id":7},{"id":8},{"id":9},{"id":10},{"id":11},{"id":12},{"id":13},{"id":14},{"id":15}] |]
 
+  describe "Shaping response with select parameter" $ do
+
+    it "selectStar works in absense of parameter" $
+      get "/complex_items?id=eq.3" `shouldRespondWith`
+        "[{\"id\":3,\"name\":\"Three\",\"settings\":{\"foo\":{\"int\":1,\"bar\":\"baz\"}}}]"
+
+    it "one simple column" $
+      get "/complex_items?select=id" `shouldRespondWith`
+        [json| [{"id":1},{"id":2},{"id":3}] |]
+
+    it "one simple column with casting (text)" $
+      get "/complex_items?select=id::text" `shouldRespondWith`
+        [json| [{"id":"1"},{"id":"2"},{"id":"3"}] |]
+
+    it "json column" $
+      get "/complex_items?id=eq.1&select=settings" `shouldRespondWith`
+        [json| [{"settings":{"foo":{"int":1,"bar":"baz"}}}] |]
+
+    it "json subfield one level with casting (json)" $
+      get "/complex_items?id=eq.1&select=settings->>foo::json" `shouldRespondWith`
+        [json| [{"foo":{"int":1,"bar":"baz"}}] |] -- the value of foo here is of type "text"
+
+    it "fails on bad casting (data of the wrong format)" $
+      get "/complex_items?select=settings->foo->>bar::integer"
+        `shouldRespondWith` ResponseMatcher {
+          matchBody    = Just [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
+        , matchStatus  = 400
+        , matchHeaders = []
+        }
+
+    it "fails on bad casting (wrong cast type)" $
+      get "/complex_items?select=id::fakecolumntype"
+        `shouldRespondWith` ResponseMatcher {
+          matchBody    = Just [json| {"hint":null,"details":null,"code":"42704","message":"type \"fakecolumntype\" does not exist"} |]
+        , matchStatus  = 400
+        , matchHeaders = []
+        }
+
+
+    it "json subfield two levels (string)" $
+      get "/complex_items?id=eq.1&select=settings->foo->>bar" `shouldRespondWith`
+        [json| [{"bar":"baz"}] |]
+
+
+    it "json subfield two levels with casting (int)" $
+      get "/complex_items?id=eq.1&select=settings->foo->>int::integer" `shouldRespondWith`
+        [json| [{"int":1}] |] -- the value in the db is an int, but here we expect a string for now
+
+
   describe "ordering response" $ do
     it "by a column asc" $
       get "/items?id=lte.2&order=id.asc"

test/Feature/StructureSpec.hs

@@ -15,6 +15,7 @@ spec = around withApp $ do
       request methodGet "/" [] ""
         `shouldRespondWith` [json| [
           {"schema":"1","name":"auto_incrementing_pk","insertable":true}
+        , {"schema":"1","name":"complex_items","insertable":true}
         , {"schema":"1","name":"compound_pk","insertable":true}
         , {"schema":"1","name":"has_count_column","insertable":false}
         , {"schema":"1","name":"has_fk","insertable":true}

test/SpecHelper.hs

@@ -13,6 +13,7 @@ import Data.Monoid
 import Data.Text hiding (map)
 import qualified Data.Vector as V
 import Control.Monad (void)
+import Control.Applicative
 
 import Network.HTTP.Types.Header (Header, ByteRange, renderByteRange,
                                   hRange, hAuthorization, hAccept)
@@ -118,6 +119,18 @@ createItems n = do
     txn = mapM_ H.unitEx stmts
     stmts = map [H.stmt|insert into "1".items (id) values (?)|] [1..n]
 
+createComplexItems :: IO ()
+createComplexItems = do
+  pool <- testPool
+  void . liftIO $ H.session pool $ H.tx Nothing txn
+  where
+    txn = mapM_ H.unitEx stmts
+    stmts = getZipList $ [H.stmt|insert into "1".complex_items (id, name, settings) values (?,?,?)|]
+        <$> ZipList ([1..3]::[Int])
+        <*> ZipList (["One", "Two", "Three"]::[Text])
+        <*> ZipList ([jobj,jobj,jobj])
+    jobj = (J.object [("foo", J.object [("int", J.Number 1),("bar", J.String "baz")])])
+
 createNulls :: Int -> IO ()
 createNulls n = do
   pool <- testPool

test/fixtures/schema.sql

@@ -47,7 +47,7 @@ SET search_path = postgrest, pg_catalog;
 CREATE FUNCTION check_role_exists() RETURNS trigger
     LANGUAGE plpgsql
     AS $$
-begin 
+begin
 if not exists (select 1 from pg_roles as r where r.rolname = new.rolname) then
    raise foreign_key_violation using message = 'Cannot create user with unknown role: ' || new.rolname;
    return null;
@@ -64,7 +64,7 @@ CREATE FUNCTION update_owner() RETURNS trigger
     LANGUAGE plpgsql
     AS $$
 BEGIN
-   NEW.owner = current_user; 
+   NEW.owner = current_user;
    RETURN NEW;
 END;
 $$;
@@ -75,8 +75,8 @@ ALTER FUNCTION postgrest.update_owner() OWNER TO postgrest_test;
 CREATE FUNCTION set_authors_only_owner() RETURNS trigger
     LANGUAGE plpgsql
     AS $$
-begin 
+begin
-  NEW.owner = current_setting('user_vars.user_id'); 
+  NEW.owner = current_setting('user_vars.user_id');
   RETURN NEW;
 end
 $$;
@@ -170,7 +170,7 @@ ALTER TABLE "1".has_fk_id_seq OWNER TO postgrest_test;
 ALTER SEQUENCE has_fk_id_seq OWNED BY has_fk.id;
 
 CREATE MATERIALIZED VIEW "1".materialized_view AS
- SELECT 
+ SELECT
     version();
 
 ALTER TABLE "1".materialized_view OWNER TO postgrest_test;
@@ -201,6 +201,15 @@ CREATE TABLE items (
 
 ALTER TABLE "1".items OWNER TO postgrest_test;
 
+CREATE TABLE complex_items (
+    id bigint NOT NULL,
+    name text,
+    settings json
+);
+
+
+ALTER TABLE "1".complex_items OWNER TO postgrest_test;
+
 
 CREATE SEQUENCE items_id_seq
     START WITH 1
@@ -407,7 +416,7 @@ ALTER FUNCTION public.always_true("1".items) OWNER TO postgrest_test;
 
 ALTER TABLE ONLY authors_only
     ADD CONSTRAINT authors_only_pkey PRIMARY KEY (secret);
-    
+
 CREATE TRIGGER insert_insertable_view_with_join INSTEAD OF INSERT ON "1".insertable_view_with_join FOR EACH ROW EXECUTE PROCEDURE "1".insert_insertable_view_with_join();
 
 
@@ -437,6 +446,8 @@ ALTER TABLE ONLY has_fk
 ALTER TABLE ONLY items
     ADD CONSTRAINT items_pkey PRIMARY KEY (id);
 
+ALTER TABLE ONLY complex_items
+    ADD CONSTRAINT complex_items_pkey PRIMARY KEY (id);
 
 
 ALTER TABLE ONLY menagerie
@@ -539,6 +550,11 @@ REVOKE ALL ON TABLE items FROM postgrest_test;
 GRANT ALL ON TABLE items TO postgrest_test;
 GRANT ALL ON TABLE items TO postgrest_anonymous;
 
+REVOKE ALL ON TABLE complex_items FROM PUBLIC;
+REVOKE ALL ON TABLE complex_items FROM postgrest_test;
+GRANT ALL ON TABLE complex_items TO postgrest_test;
+GRANT ALL ON TABLE complex_items TO postgrest_anonymous;
+
 
 REVOKE ALL ON FUNCTION getitemrange(bigint, bigint) FROM PUBLIC;
 REVOKE ALL ON FUNCTION getitemrange(bigint, bigint) FROM postgrest_test;