在sql中，可以使用select语句删除重复数据，语法为：“select * from 字段 where 字段id in (select 字段id from 字段 group by 字段 having count(字段id) > 1)”。
本教程操作环境：windows7系统、mysql8.0版本、dell g3电脑。
用sql语句,删除掉重复项只保留一条
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
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)
扩展：
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 peoplewhere peoplename in (select peoplename from people group by peoplename having count(peoplename) > 1)and peopleid not in (select min(peopleid) from people group by peoplename having count(peoplename)>1)
查找表中多余的重复记录（多个字段）
select * from vitae awhere (a.peopleid,a.seq) in (select peopleid,seq from vitae group by peopleid,seq having count(*) > 1)
删除表中多余的重复记录（多个字段），只留有rowid最小的记录
delete from vitae awhere (a.peopleid,a.seq) in (select peopleid,seq from vitae group by peopleid,seq having count(*) > 1)and rowid not in (select min(rowid) from vitae group by peopleid,seq having count(*)>1)
查找表中多余的重复记录（多个字段），不包含rowid最小的记录
select * from vitae awhere (a.peopleid,a.seq) in (select peopleid,seq from vitae group by peopleid,seq having count(*) > 1)and rowid not in (select min(rowid) from vitae group by peopleid,seq having count(*)>1)
消除一个字段的左边的第一位：
update tablename set [title]=right([title],(len([title])-1)) where title like '村%'
消除一个字段的右边的第一位：
update tablename set [title]=left([title],(len([title])-1)) where title like '%村'
假删除表中多余的重复记录（多个字段），不包含rowid最小的记录
update vitae set ispass=-1where peopleid in (select peopleid from vitae group by peopleid
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以上就是sql如何删除重复数据的详细内容。