INNER JOIN `user` ON `user`.`uid` = `thread`.`uid` AND NOT `user`.`hidewall`
INNER JOIN `item` ON `item`.`id` = `thread`.`iid`
AND `item`.`allow_cid` = '' AND `item`.`allow_gid` = ''
INNER JOIN `user` ON `user`.`uid` = `thread`.`uid` AND NOT `user`.`hidewall`
INNER JOIN `item` ON `item`.`id` = `thread`.`iid`
AND `item`.`allow_cid` = '' AND `item`.`allow_gid` = ''