Merge where() and having() logic - it's structurally identical and only the keyword differs
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index a6e2a62..ee5af78 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -394,7 +394,7 @@
 
 		$this->where($index.' IN('.implode(',', $ids).')', NULL, FALSE);
 
-		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_where();
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2).$this->_compile_wh('qb_where');
 	}
 
 	// --------------------------------------------------------------------