重複記錄查詢

1、重複記錄查詢
1.1 方法簡介
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)

1.2 實例
在表WBS_CORRESPONDENCE中查詢 WBSCODE 重複的數據
SELECT * from WBS_CORRESPONDENCE where WBSCODE in( SELECT WBSCODE from WBS_CORRESPONDENCE GROUP BY WBSCODE HAVING “COUNT”(WBSCODE)>1)