Fix an issue introduced in 88cb278a1e52dd7db5b0ebe2037c12f0dd69c0c1
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index b99d4c6..645ac39 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -965,7 +965,7 @@
 		}
 		elseif ($direction !== $this->_random_keyword && $escape === TRUE)
 		{
-			$part = preg_match('/^(.+)\s+(ASC|DESC)$/i', $orderby, $matches)
+			$orderby = preg_match('/^(.+)\s+(ASC|DESC)$/i', $orderby, $matches)
 				? $this->protect_identifiers(rtrim($matches[1])).' '.$matches[2]
 				: $this->protect_identifiers($orderby);
 		}