From 765ed250697b52e5c0fdc78bbe5532271d66c255 Mon Sep 17 00:00:00 2001
From: Greg Sabino Mullane <greg@users.mediawiki.org>
Date: Tue, 2 Jan 2007 21:34:42 +0000
Subject: [PATCH] Add implicitGroupby function to account for different
 database behaviors.

---
 includes/Database.php          | 7 +++++++
 includes/DatabasePostgres.php  | 4 ++++
 includes/SpecialCategories.php | 3 ++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/includes/Database.php b/includes/Database.php
index 14764bd8fd..eb1ee1359c 100644
--- a/includes/Database.php
+++ b/includes/Database.php
@@ -369,6 +369,13 @@ class Database {
 		return false;
 	}
 
+	/**
+	 * Returns true if this database does an implicit sort when doing GROUP BY
+	 */
+	function implicitGroupby() {
+		return true;
+	}
+
 	/**#@+
 	 * Get function
 	 */
diff --git a/includes/DatabasePostgres.php b/includes/DatabasePostgres.php
index b78e6d5c51..803c0e26fb 100644
--- a/includes/DatabasePostgres.php
+++ b/includes/DatabasePostgres.php
@@ -37,6 +37,10 @@ class DatabasePostgres extends Database {
 		return true;
 	}
 
+	function implicitGroupby() {
+		return false;
+	}
+
 	static function newFromParams( $server = false, $user = false, $password = false, $dbName = false,
 		$failFunction = false, $flags = 0)
 	{
diff --git a/includes/SpecialCategories.php b/includes/SpecialCategories.php
index 89cff20a05..346eac633d 100644
--- a/includes/SpecialCategories.php
+++ b/includes/SpecialCategories.php
@@ -30,10 +30,11 @@ class CategoriesPage extends QueryPage {
 		$NScat = NS_CATEGORY;
 		$dbr =& wfGetDB( DB_SLAVE );
 		$categorylinks = $dbr->tableName( 'categorylinks' );
+		$implicit_groupby = $dbr->implicitGroupby() ? '1' : 'cl_to';
 		$s= "SELECT 'Categories' as type,
 				{$NScat} as namespace,
 				cl_to as title,
-				1 as value,
+				$implicit_groupby as value,
 				COUNT(*) as count
 			   FROM $categorylinks
 			   GROUP BY 1,2,3,4";
-- 
2.20.1