Database Problem

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 '' at line 4
SELECT, sites.title, sites.url, sites.imgurl, sites.urlrss, sites.facebook, sites.googleplus, sites.twitter,, sites.urlmobile,,, sites.language,, sites.type, sites.plot, userdata.data_id as favorite FROM sites LEFT JOIN userdata ON userdata.data_id = AND userdata.cat_data = "site" AND userdata.user_id = 10000 WHERE =