刪除表中重復數據sql語句

查詢表中重復數據
select * from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1)

刪除表中多余的重復記錄，重復記錄是根據單個字段（employeeId）來判斷，只留有rowid最小的記錄
delete from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1)
and rowid not in (select min(rowid) from employee group by employeeId having count(employeeId )>1)

查找表中多余的重復記錄（多個字段）
select * from employee e
where (e.employeeId,e.phoneNo) in (select employeeId,phoneNo from employee group by employeeId,phoneNo having count(*) > 1)

刪除表中多余的重復記錄（多個字段），只留有rowid最小的記錄
delete from employee e
where (e.employeeId, e.phoneNo) in (select employeeId, phoneNo from employee group by employeeId,phoneNo having count(*) > 1)
and rowid not in (select min(rowid) from employee group by employeeId,phoneNo having count(*)>1)

查找表中多余的重復記錄（多個字段），不包含rowid最小的記錄
select * from employee e
where (e.employeeId,e.phoneNo) in (select employeeId, phoneNo from employee group by employeeId,phoneNo having count(*) > 1)
and rowid not in (select min(rowid) from employee group by employeeId,phoneNo having count(*)>1)

通用:

delete from table t
where (t.字段1, t.字段2, … , t.字段n) in (select 字段1, 字段2, … , 字段n from table group by 字段1, 字段2, … , 字段n having count(*) > 1)
and rowid not in (select min(rowid) from table group by 字段1, 字段2, … , 字段n having count(*)>1)

此外:

如果只是查詢的時候, 不顯示重復, 只需select distinct 字段 from table….

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原文鏈接：https://blog.csdn.net/germoo/article/details/79960480