tw: fix cleanup function

Signed-off-by: Varun Patil <radialapps@gmail.com>

lib/Db/TimelineWrite.php

@@ -221,17 +221,22 @@ class TimelineWrite
         // Begin transaction
         $this->connection->beginTransaction();
 
-        // Existence clause
-        $clause = 'SELECT 1 FROM *PREFIX*filecache AS f
-                   WHERE f.fileid=m.fileid
-                   AND f.path NOT LIKE "files_trashbin/%"';
-
         // Delete all stale records
         foreach (DELETE_TABLES as $table) {
-            // Query builder doesn't add the table to delete from,
-            // so we use need to use raw SQL here :/
-            $sql = "DELETE m FROM *PREFIX*{$table} m WHERE NOT EXISTS ({$clause})";
-            $this->connection->executeStatement($sql);
+            $query = $this->connection->getQueryBuilder();
+            $clause = $query
+                ->select($query->expr()->literal('1'))
+                ->from('filecache', 'f')
+                ->where($query->expr()->eq('f.fileid', "*PREFIX*{$table}.fileid"))
+                ->andWhere($query->expr()->notLike('f.path', $query->expr()->literal('files_trashbin/%')))
+                ->getSQL()
+            ;
+
+            $query = $this->connection->getQueryBuilder();
+            $query->delete($table)
+                ->where($query->createFunction("NOT EXISTS({$clause})"))
+                ->executeStatement()
+            ;
         }
 
         // Commit transaction