select username+'-'+userpwd as zd from user where zd='admin-1111' ，我用这个语句为什么出现 列名zd无效 的错误？
前面部分select username+'-'+userpwd as zd from user 是可以查询的
如何修改？
别名不能用在查询条件里吧。
select username+'-'+userpwd as zd from user where username+'-'+userpwd='admin-1111'
select username+'-'+userpwd as zd from user where username+'-'+userpwd='admin-1111'
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第1个回答 2010-07-15
zd 不能在where条件中使用
select username+'-'+userpwd as zd
from user
where username='admin'
and userpwd ='1111'
select username+'-'+userpwd as zd
from user
where username='admin'
and userpwd ='1111'
第2个回答 2010-07-15
select username+'-'+userpwd as zd from [user] where username+'-'+userpwd='admin-1111'
