From 8783615ebcf06b6066230abfa8a2ad428e168d79 Mon Sep 17 00:00:00 2001
From: Ruslan Talpa <ruslan.talpa@gmail.com>
Date: Thu, 24 Sep 2015 23:30:47 +0300
Subject: [PATCH] detect primary keys for views (fix #217)

---
 src/PostgREST/PgStructure.hs  | 35 ++++++++++----
 test/Feature/StructureSpec.hs | 88 +++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 10 deletions(-)

diff --git a/src/PostgREST/PgStructure.hs b/src/PostgREST/PgStructure.hs
index 9e5647b8a..2a79b7610 100644
--- a/src/PostgREST/PgStructure.hs
+++ b/src/PostgREST/PgStructure.hs
@@ -110,16 +110,31 @@ columns table = do
 primaryKeyColumns :: QualifiedIdentifier -> H.Tx P.Postgres s [Text]
 primaryKeyColumns table = do
   r <- H.listEx $ [H.stmt|
-    select kc.column_name
-      from
-        information_schema.table_constraints tc,
-        information_schema.key_column_usage 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 kc.table_schema = ?
-      and kc.table_name  = ? |] (qiSchema table) (qiName table)
+      WITH table_pk AS
+      ( SELECT kc.table_schema,
+               kc.table_name,
+               kc.column_name
+       FROM information_schema.table_constraints tc,
+            information_schema.key_column_usage 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 kc.table_schema = ?)
+      SELECT column_name
+      FROM table_pk
+      WHERE table_pk.table_name = ?
+      UNION
+      (
+       SELECT vcu.column_name
+       FROM information_schema.view_column_usage AS vcu
+       JOIN table_pk ON table_pk.table_schema = vcu.view_schema
+        AND table_pk.TABLE_NAME = vcu.TABLE_NAME
+        AND table_pk.column_name = vcu.column_name
+       WHERE vcu.view_schema = ?
+         AND vcu.view_name = ?
+      )
+    |] (qiSchema table) (qiName table) (qiSchema table) (qiName table)
   return $ map runIdentity r
 
 doesProcExist :: Text -> Text -> H.Tx P.Postgres s Bool
diff --git a/test/Feature/StructureSpec.hs b/test/Feature/StructureSpec.hs
index f63628e8a..d2f6bdb45 100644
--- a/test/Feature/StructureSpec.hs
+++ b/test/Feature/StructureSpec.hs
@@ -145,6 +145,94 @@ spec = around withApp $ do
       }
       |]
 
+    it "it includes primary key for views" $
+      request methodOptions "/insertable_view_with_join" [] "" `shouldRespondWith`
+      [json|
+      {
+         "pkey":["id"],
+         "columns":[
+            {
+               "references":null,
+               "default":null,
+               "precision":64,
+               "updatable":false,
+               "schema":"1",
+               "name":"id",
+               "type":"bigint",
+               "maxLen":null,
+               "enum":[],
+               "nullable":true,
+               "position":1
+            },
+            {
+               "references":null,
+               "default":null,
+               "precision":32,
+               "updatable":false,
+               "schema":"1",
+               "name":"auto_inc_fk",
+               "type":"integer",
+               "maxLen":null,
+               "enum":[],
+               "nullable":true,
+               "position":2
+            },
+            {
+               "references":null,
+               "default":null,
+               "precision":null,
+               "updatable":false,
+               "schema":"1",
+               "name":"simple_fk",
+               "type":"character varying",
+               "maxLen":255,
+               "enum":[],
+               "nullable":true,
+               "position":3
+            },
+            {
+               "references":null,
+               "default":null,
+               "precision":null,
+               "updatable":false,
+               "schema":"1",
+               "name":"nullable_string",
+               "type":"character varying",
+               "maxLen":null,
+               "enum":[],
+               "nullable":true,
+               "position":4
+            },
+            {
+               "references":null,
+               "default":null,
+               "precision":null,
+               "updatable":false,
+               "schema":"1",
+               "name":"non_nullable_string",
+               "type":"character varying",
+               "maxLen":null,
+               "enum":[],
+               "nullable":true,
+               "position":5
+            },
+            {
+               "references":null,
+               "default":null,
+               "precision":null,
+               "updatable":false,
+               "schema":"1",
+               "name":"inserted_at",
+               "type":"timestamp with time zone",
+               "maxLen":null,
+               "enum":[],
+               "nullable":true,
+               "position":6
+            }
+         ]
+      }
+      |]
+
     it "includes foreign key data" $ do
       pendingWith "have to resolve issue #107"