BBP_Converter_Base::convert_forum_parents( $start )

	public function convert_forum_parents( $start ) {

		$has_update = false;

		if ( !empty( $this->sync_table ) ) {
			$query = 'SELECT value_id, meta_value FROM ' . $this->sync_table_name . ' WHERE meta_key = "_bbp_forum_parent_id" AND meta_value > 0 LIMIT ' . $start . ', ' . $this->max_rows;
		} else {
			$query = 'SELECT post_id AS value_id, meta_value FROM ' . $this->wpdb->postmeta . ' WHERE meta_key = "_bbp_forum_parent_id" AND meta_value > 0 LIMIT ' . $start . ', ' . $this->max_rows;
		}

		update_option( '_bbp_converter_query', $query );

		$forum_array = $this->wpdb->get_results( $query );

		foreach ( (array) $forum_array as $row ) {
			$parent_id = $this->callback_forumid( $row->meta_value );
			$this->wpdb->query( 'UPDATE ' . $this->wpdb->posts . ' SET post_parent = "' . $parent_id . '" WHERE ID = "' . $row->value_id . '" LIMIT 1' );
			$has_update = true;
		}

		return ! $has_update;
	}