From ba31b5beb315d66a85e118edea428b3e1c8017ed Mon Sep 17 00:00:00 2001
From: Greg Sabino Mullane <greg@users.mediawiki.org>
Date: Thu, 19 Apr 2007 01:35:15 +0000
Subject: [PATCH] Add constraintExists function, mild cleanup of other nearby
 funcs.

---
 includes/DatabasePostgres.php | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/includes/DatabasePostgres.php b/includes/DatabasePostgres.php
index 4e28dc146e..f2b982d629 100644
--- a/includes/DatabasePostgres.php
+++ b/includes/DatabasePostgres.php
@@ -880,7 +880,7 @@ class DatabasePostgres extends Database {
 	}
 
 	function triggerExists($table, $trigger) {
-	global $wgDBmwschema;
+		global $wgDBmwschema;
 
 		$q = <<<END
 	SELECT 1 FROM pg_class, pg_namespace, pg_trigger
@@ -892,14 +892,15 @@ END;
 				$this->addQuotes($wgDBmwschema),
 				$this->addQuotes($table),
 				$this->addQuotes($trigger)));
-		$row = $this->fetchRow($res);
-		$exists = !!$row;
+		if (!$res)
+			return NULL;
+		$rows = pg_num_rows($res);
 		$this->freeResult($res);
-		return $exists;
+		return $rows;
 	}
 
 	function ruleExists($table, $rule) {
-	global $wgDBmwschema;
+		global $wgDBmwschema;
 		$exists = $this->selectField("pg_rules", "rulename",
 				array(	"rulename" => $rule,
 					"tablename" => $table,
@@ -907,6 +908,21 @@ END;
 		return $exists === $rule;
 	}
 
+	function constraintExists($table, $constraint) {
+		global $wgDBmwschema;
+		$SQL = sprintf("SELECT 1 FROM information_schema.table_constraints ".
+			   "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
+			$this->addQuotes($wgDBmwschema),	
+			$this->addQuotes($table),	
+			$this->addQuotes($constraint));
+		$res = $this->query($SQL);
+		if (!$res)
+			return NULL;
+		$rows = pg_num_rows($res);
+		$this->freeResult($res);
+		return $rows;
+	}
+
 	/**
 	 * Query whether a given schema exists. Returns the name of the owner
 	 */
-- 
2.20.1