今天在查詢一個表時,用下面的語句
select distinct concat(slipno,'|',date_format(ydate,'%Y-%m-%d')) as code,slipno as name from bus_cchecks;
結果是:

code name
o080414001|200 o080414001

如果將distinct去掉,結果正常,但會重復
code name
o080414001|2008-04-15 o080414001
o080414001|2008-04-15 o080414001
o080414001|2008-04-15 o080414001
o080414001|2008-04-15 o080414001
o080414001|2008-04-15 o080414001
o080414001|2008-04-15 o080414001

後來改用下面的語句
select  concat(slipno,'|',date_format(ydate,'%Y-%m-%d')) as code,slipno as name from bus_cchecks group by slipno,ydate;
結果正常:
code name
o080414001|2008-04-15 o080414001

posted on 2008-04-14 14:51  小哈  阅读(147)  评论(0编辑  收藏  举报