select name,sum(num) from table group by name
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--group by 分组查询可以实现，根据名称分组查询累加数量
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
select * from tableName where (bookname,borrowtime) in (select bookname,borrowtime from tableName group by bookname,borrowtime having count(*) 1);
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
