几个实用的SQL语句

bjourway

在对数据进行分析处理时，有时候会遇到要处理重复记录的问题，下面分享下针对重复记录的几个SQL语法。
http://www.powerbibbs.com/thread-184-1-1.html

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)

斐来飞去

很好 学习了

fcz1184583148

{:soso_e179:}学习了{:soso_e176:}

bjourway

fcz1184583148 发表于 2012/12/19 23:16
学习了

{:soso_e128:}{:soso_e181:}