【新手求助】两段查询命令分析 不知道错哪了?
1)此查询命令运行后 priv_more表自动删除了,不知道为什么 若不用 drop table priv_more 则显示语法错误?drop table priv_more select hm, count(hm) as expr1 into priv_more from tt where fx=1 or fx = 2 or (fx>432 and fx<443) group by hm;
having (count(hm) > 1) select * from priv_more select id,hm,fx,je from tt where hm in (select hm from priv_more)
2)此命令并没有检查出错误,但查询的时候容易卡死,40万的数据 查半天也不会走。
select * from tt,tt1 where tt.fx=tt1.fx and tt.hm=tt1.hm and tt.je<>tt1.je and tt.je>0 and tt1.je>0
以上两个查询命令 求教高手帮忙解释下,谢谢了