就是一个表里的记录很多的时候就会有这个问题 如果一个表里的记录少的话是没有这个问题的 为什么呀!?我的sql 语句如下: select * from administrator as a,(select username from administrator group by username having count(*)>1)b where a.username = b.username
……administrator表里面本来就有两条相同的记录吧干吗不写成这样? select * from administrator as a where a.username in (select username from administrator group by username having count(*)>1)
select distinct * from administrator as a,(select username from administrator group by username having count(*)>1)b where a.username = b.username你的表里本来就有重复的记录,你那样写是可以把重复的记录取出来,可取出来的既然是'重复的记录'当然就不可能是一条了。加distinct
如果一个表里的记录少的话是没有这个问题的
为什么呀!?我的sql 语句如下:
select * from administrator as a,(select username from administrator group by username having count(*)>1)b where a.username = b.username
select * from administrator as a where a.username in (select username from administrator group by username having count(*)>1)
我就是想select出一个表里的重复记录
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1 | 100克虾皮和100克芝麻酱哪个含钙量高?
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1 | 100克虾皮和100克芝麻酱哪个含钙量高?
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我就是想查一下同一个表里的重复纪录(通过字段Title)。麻烦大家给个好的sql语句!谢谢!
这就可以看到重复纪录了