A fatal MySQL error occurred.

Query:
SELECT id, title, friendly_url, logo_extension FROM pmd_listings WHERE status = 'active' AND featured = 1 AND location_id= AND logo_extension !='' ORDER by RAND() LIMIT 0, 16

Error:
(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 'AND logo_extension !='' ORDER by RAND() ' at line 11