Id name age salary
1 yzk 8010002 yzk 8020003 tom 20200004 tom 20200005 im 20200001:使用Distinct 去重
SELECT DISTINCT Name FROM Persons(Distinct 只能去除结果集中一模一样的数据)
获取不重复数据思考1:
SELECT Name, age FROM Persons GROUP BY Name, Gender
获取不重复数据思考2:
SELECT MAX(Id) AS Expr1, Name, Gender FROM Persons GROUP BY Name, age
获取不重复数据:
select * from Persons where Id in ( SELECT MAX(Id) AS Expr1 FROM Persons GROUP BY Name, age )
删除重复的数据:
delete from Persons where Id not in ( SELECT MAX(Id) AS Expr1 FROM Persons GROUP BY Name, age )