有一个表导数据时导入了重复的数据,现在家主键家不上啊,如何查看和删除! 在线求救!! 如果ID为主键,且有列col可按ID区分大小.--查询 select * from tb where id in (select id from tb group by id having count(*) > 1)--删除 delete from tb where col not in (select min(col) from tb group by id )
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、删除表中多余的重复记录(多个字段),只留有rowid最小的记录 delete from vitae a where (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)5、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 a where (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)
为什么不可以用他查出来的select * from tb where id in (select id from tb group by id having count(*) > 1) 来删除啊
如果ID为主键,且有列col可按ID区分大小. 是什么意思啊
如果ID为主键,且有列col可按ID区分大小. 是什么意思啊就是说主键ID重复的值,有一个其他列(col)可区分其大小,这样可以在删除时留住最大(或最小)的那行.如果所有列都不能区分大小,则只有使用临时表了.如 id col id col 1 1 1 1 1 1 1 2 1 2 1 3 2 1 2 1 2 2 2 2 2 3 3 1
查有重复记录的。 select col1,col2,col3 from tablename group by col1,col2,col3 having count(*)>1
在线求救!!
如果ID为主键,且有列col可按ID区分大小.--查询
select * from tb where id in (select id from tb group by id having count(*) > 1)--删除
delete from tb where col not in (select min(col) from tb group by id )
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、删除表中多余的重复记录(多个字段),只留有rowid最小的记录
delete from vitae a
where (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)5、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 a
where (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)
来删除啊
是什么意思啊
是什么意思啊就是说主键ID重复的值,有一个其他列(col)可区分其大小,这样可以在删除时留住最大(或最小)的那行.如果所有列都不能区分大小,则只有使用临时表了.如
id col id col
1 1 1 1
1 1 1 2
1 2 1 3
2 1 2 1
2 2 2 2
2 3 3 1
select col1,col2,col3 from tablename group by col1,col2,col3 having count(*)>1