SQL中删除重复记录-mysql教程

Create Table dbo.Employee

([Id] int Primary KEY ,

[Name] varchar(50),

[Age] int,

[Sex] bit default 1)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(1,'James',25,default)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(2,'James',25,default)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(3,'James',25,default)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(4,'Lisa',24,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(5,'Lisa',24,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(6,'Lisa',24,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(7,'Mirsa',23,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(8,'Mirsa',23,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(9,'Mirsa',23,0)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(10,'John',26,default)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(11,'Abraham',28,default)

Insert Into Employee ([Id] , [Name] , [Age] , [Sex] ) Values(12,'Lincoln',30,default)

Select * From dbo.Employee

Delete From Employee Where Name in (

Name

From Employee Group By Name Having Count(Name)>1);

Delete T From(

Select Row_Number() Over(Partition By [Name] Order By (SELECT 0)) As RowNumber,* From Employee) T

Where T.RowNumber > 1;

With Du as

(

select ROW_NUMBER() Over(Partition by [Name] Order by (SELECT 0)) as rn

FROM Employee

)

Delete From Dups

Where rn>1;

WITH Dups As

(

Select [ID],[Name],[Age],[Sex]

, ROW_NUMBER() OVER(Partition By [Name] Order By (SELECT 0)) AS rn

,RANK() OVER(Partition By [Name] Order By (SELECT 0)) AS rnk

FROM Employee

)

DELETE FROM Dups

WHERE rn<>rnk;

WITH Dups As

(

Select [ID],[Name],[Age],[Sex]

, ROW_NUMBER() OVER(Partition By [ID] Order By (SELECT 0)) AS rn

FROM Employee

)

Select [ID],[Name],[Age],[Sex]

INTO dbo.EmployeeDupsTmp

FROM Dups

WHERE rn=1

DROP TABLE dbo.Employee;

EXEC sp_rename 'dbo.EmployeeDupsTmp','Employee'