From 0fc654981a86f5f0c41d5727f93907e7895dc140 Mon Sep 17 00:00:00 2001
From: David Binney <d.binney@cqu.edu.au>
Date: Tue, 8 Mar 2016 16:58:17 +1000
Subject: [PATCH] gh #8160 : @markstory, Updating query to allow for multi
 column constraints and composite keys

---
 src/Database/Schema/PostgresSchema.php | 40 ++++++++++++--------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/src/Database/Schema/PostgresSchema.php b/src/Database/Schema/PostgresSchema.php
index f8f1a5b8b37..e271a127e33 100644
--- a/src/Database/Schema/PostgresSchema.php
+++ b/src/Database/Schema/PostgresSchema.php
@@ -191,27 +191,25 @@ protected function _defaultValue($default)
      */
     public function describeIndexSql($tableName, $config)
     {
-        $sql = 'SELECT
-            c2.relname,
-            a.attname,
-            i.indisprimary,
-            i.indisunique
-        FROM pg_catalog.pg_class AS c,
-            pg_catalog.pg_class AS c2,
-            pg_catalog.pg_index AS i,
-            pg_catalog.pg_attribute AS a
-        WHERE c.oid  = (
-            SELECT c.oid
-            FROM pg_catalog.pg_class c
-            LEFT JOIN pg_catalog.pg_namespace AS n ON n.oid = c.relnamespace
-            WHERE c.relname = ?
-                AND n.nspname = ?
-        )
-        AND c.oid = i.indrelid
-        AND c.oid = a.attrelid
-        AND a.attnum = ANY(i.indkey)
-        AND i.indexrelid = c2.oid
-        ORDER BY i.indisprimary DESC, i.indisunique DESC, c2.relname, a.attnum';
+        $sql = "SELECT
+            c.conname AS name,
+            c.contype AS type,
+            a.attname AS column_name,
+            c.confmatchtype AS match_type,
+            c.confupdtype AS on_update,
+            c.confdeltype AS on_delete,
+            c.confrelid::regclass AS references_table,
+            ab.attname AS references_field
+        FROM pg_catalog.pg_namespace n
+        INNER JOIN pg_catalog.pg_constraint c ON (n.oid = c.connamespace)
+        INNER JOIN pg_catalog.pg_class cl ON (cl.oid = c.conrelid)
+        INNER JOIN pg_catalog.pg_attribute a ON (a.attrelid = cl.oid AND c.conrelid::regclass = a.attrelid::regclass)
+        INNER JOIN pg_catalog.pg_attribute ab ON (ab.attrelid = cl.oid AND a.attrelid = ab.attrelid AND a.attnum = ab.attnum)
+        WHERE n.nspname = ?
+        AND a.attnum = any(c.conkey)
+        AND c.conrelid = ?::regclass
+        AND c.contype='f'
+        ORDER BY c.conname, a.attnum";
 
         $schema = 'public';
         if (!empty($config['schema'])) {