大家好是有可能重写查询:重写子查询(不)作为加入
select userid from User where userid not in(select userid from UserRole where roleid in(8));
的加入?
问题是,一个用户可能有几个角色
谢谢你提前。
mysql> desc User; +--------------------+-------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +--------------------+-------------------+------+-----+---------+----------------+ | userId | int(11) | NO | PRI | NULL | auto_increment | | userName | varchar(50) | YES | | NULL | |
...等用户相关的列
mysql> desc UserRole; +--------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+---------+------+-----+---------+-------+ | userId | int(11) | NO | PRI | 0 | | | roleId | int(11) | NO | PRI | 0 | | +--------+---------+------+-----+---------+-------+
我闻到作业... – cletus 2009-01-05 11:22:38