SQL查找列（字段）重複值及操作

1、查找表中多餘的重複記錄，重複記錄是根據單個字段（peopleId）來判斷

select * from people
where peopleId in (select   peopleId from   people group by   peopleId having count(peopleId) > 1)

2、刪除表中多餘的重複記錄，重複記錄是根據單個字段（peopleId）來判斷，只留有rowid最小的記錄

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、查找表中多餘的重複記錄（多個字段） 

select * from vitae a
where (a.peopleId,a.seq) in   (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)

4、刪除表中多餘的重複記錄（多個字段），只留有rowid最小的記錄

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、查找表中多餘的重複記錄（多個字段），不包含rowid最小的記錄

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)