DB Error: selectSingle query failed

SELECT file_attachments.*, channels.name AS channel, files.name, files.ext, files.type_id FROM file_attachments LEFT JOIN files ON files.id = file_attachments.file_id LEFT JOIN channels ON channels.id = file_attachments.channel_id WHERE channels.name = 'droetker_contests_headers' AND object_id = AND main = 1

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 main = 1' at line 11