How To Remove or Delete duplicate records from Sql server database

Three different methods of deleting duplicate records from sql server database table.

First Method :-->

First of all create table
Code
 create table Temp	(Id int IDENTITY(1,1),FirstName	varchar(50),Description varchar(50)	)

Insert values
Code
 insert into Temp(FirstName,Description) Values('name4','dept4')

untitled1.bmp
Perform Operation for deleting Duplicates Records ,
Code
 select * from Temp
SELECT MIN(ID) FROM Temp GROUP BY FirstName,Description

Delete FROM Temp
WHERE ID NOT IN (SELECT MIN(ID)
FROM Temp GROUP BY FirstName,Description)


untitled2.bmp
Second Method :-->

SQL
 WITH DuplicateRecords AS
(
SELECT *,row_number() OVER(PARTITION BY FirstName,Description ORDER BY 

FirstName) 
AS RowNumber FROM Temp
)
Delete FROM DuplicateRecords WHERE RowNumber>1

Third Method :-->
SQL
 SELECT DISTINCT * INTO TempTable FROM Temp
GROUP BY FirstName,Description,Id
HAVING COUNT(FirstName) > 1

select Temp WHERE FirstName
IN (SELECT FirstName FROM TempTable)

DELETE Temp WHERE FirstName
IN (SELECT FirstName FROM TempTable)

INSERT Temp SELECT * FROM TempTable
DROP TABLE TempTable

untitled3.bmp