备用sql 语句

1、

$sql="select `id`,`cardcode`,`addday`,`addtime`,if(`cardstate`='1','已使用','未使用'),useday,usetime,username from `card` order by id desc LIMIT ".$p->limit(); 

2、

$userId = implode(',',$_POST['check']);

mysql_query("DELETE FROM `card` WHERE `id` IN ($userId)");