mysql 查重复的数据（主键除外）

select distinct biao.id

from biao

left outer join (select col1, col2

from biao

group by col1, col2

having count(*) >1) tmp

on biao.col1 = tmp.col1

and biao.col2 = tmp.col2

你是要查找数据库中某个字段下的相同数据吧，我给你写2个例子

(数据库执行效率高)

select * from dbo.MediafileInfo as a where

(VideoDownUrl IN (SELECT VideoDownUrl FROM MediafileInfo AS B WHERE A.ProgramID <>B.ProgramID))

(数据库执行效率低)

SELECT *

FROM MediafileInfo AS A

WHERE (SELECT COUNT(*) FROM MediafileInfo WHERE VideoDownUrl=A.VideoDownUrl)>1

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