MySQL error

Method: Db::query()
Query:
SELECT   * 

FROM    itm_catalog

WHERE   parent=

ORDER BY sorting ASC 

Answer: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ORDER BY sorting ASC' at line 7

In: /home/itmarketua/domains/itmarket.net.ua/public_html/applications/models/catalog/model.catalog.php
Line: 238