A Database Error Occurred

Error Number: 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 cat_name' at line 1

SELECT id,cat_name,id_parent FROM categories WHERE id_parent= ORDER BY cat_name

Filename: /home/c/cl67381/public_html/models/cat.php

Line Number: 123