SQL删除指定字段问题
更新下问题：
表：TBL_Info
字段：
infoId int
title varchar(20)
Content text
byUser varchar(20)
createTime datetime
1、如何删除表中数据相同的数据呢？（主键除外）
2、如何删除数据表中某个字段数据相同的数据呢(比如title：删除所有title相同的数据)？
3、如何统计表中title相同数据的数目？
--1
--1.1相同时保留最小的infoId
delete TBL_Info from TBL_Info t where infoId not in (select min(id) from infoId where title = t.title and Content = t.Content and byUser = t.byUser and createTime = t.createTime)
--1.1相同时保留最大的infoId
delete TBL_Info from TBL_Info t where infoId not in (select max(id) from infoId where title = t.title and Content = t.Content and byUser = t.byUser and createTime = t.createTime)
--2
delete from TBL_Info where title in (select title from TBL_Info group by title having count(1) > 1)
--3
select title , count(1) from TBL_Info group by title
select title , count(*) from TBL_Info group by title
select title , count(title) from TBL_Info group by title
--功能概述:删除重复记录
在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢?谢谢!
1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录
delete from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)
3、查找表中多余的重复记录（多个字段）
select * from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
4、删除表中�
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