急inner join 有关问题

急。。inner join 问题

select     a.*   from   member_1   as   a   inner   join   tb_game_chat   b   on   a.mem_id   <>   b.g_id   where   a.mem_type= '0 '


请问为什么不能用 <> 呢？？结果是查询了多次
我想实现   查询表a不等于表b的

------解决方案--------------------------------------------------------
用 <> 就相当于交叉联接
------解决方案--------------------------------------------------------
你这个比较麻烦...

应该是先用inner join求出相等的

再求a 和 相等的集合的差集
------解决方案--------------------------------------------------------
<> 的到的是乘积的查询
------解决方案--------------------------------------------------------
select a.* ,b.g_id from member_1 as a inner join tb_game_chat b on (1=1) where a.mem_type= '0 ' and a.mem_id <> b.g_id
------解决方案--------------------------------------------------------
not in 或者 not exists。例如：

select * from member_1 as a where mem_type= '0 ' and not exists(select * from tb_game_chat where g_id=a.mem_id)
------解决方案--------------------------------------------------------
select a.* from member_1 as a inner join tb_game_chat b on a.mem_id <> b.g_id where a.mem_type= '0 '

-------------------------------------------------------------------------------
select * from member_1 where mem_id not in(select g_id from tb_game_chat) and mem_type= '0 '

用子查询不要用连接，虽然not in不是很好的方法可是也比用连接好一点