ORACLE查詢重複資料
阿新 • • 發佈:2021-10-20
1、查詢表中多餘的重複記錄,重複記錄是根據單個欄位(userCode)來判斷
select * from user where userCode in (select userCode from user group by userCode having count (userCode) > 1)
2、刪除表中多餘的重複記錄,重複記錄是根據單個欄位(userCode)來判斷,只留有rowid最小的記錄
delete from user where userCode in (select userCode fromuser group by userCode having count (peopleId) > 1) and rowid not in (select min(rowid) from user group by userCode having count(userCode)>1)
3、查詢表中多餘的重複記錄(多個欄位)
select * from user a where (a.userCode,a.userName) in (select userCode,userName from user group byuserCode,userName having count(*) > 1)
4、刪除表中多餘的重複記錄(多個欄位),只留有rowid最小的記錄
delete from user a where (a.userCode,a.userName) in (select userCode,userName from user group by userCode,userName having count(*) > 1) and rowid not in (select min(rowid) from user group by userCode,userName havingcount(*)>1)
5、查詢表中多餘的重複記錄(多個欄位),不包含rowid最小的記錄
select * from user a where (a.userCode,a.userName) in (select userCode,userName from user group by userCode,userName having count(*) > 1) and rowid not in (select min(rowid) from user group by userCode,userName having count(*)>1)好的程式碼像粥一樣,都是用時間熬出來的