MySQL server error report:Array ( [0] => Array ( [message] => MySQL Query Error ) [1] => Array ( [sql] => SELECT * FROM `astscm`.`hhs_ad` where position_id=1 and (city_id =47317 or city_id =) ORDER BY ad_id desc limit 10 ) [2] => Array ( [error] => 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 ad_id desc limit 10' at line 1 ) [3] => Array ( [errno] => 1064 ) )