Write a query to Update the Male <->Female in SQL server

 update tableA set Gender = (case gender ='Male' then 'Female' else 'Male' end)

Create Stored Procedure with output parameter and how to call stored procedure with output.

 Create proc with input parameter:

CREATE PROCEDURE Usp_GetEmployee

(

   @EmpId int

)

as

begin

select * from Emp where EmpId=@EmpId

end

 Create proc with Output parameter:

CREATE PROC Usp_OutPutEmp

(

  @EmpId int ,

  @empName varchar output

)

as 

begin

SELECT @empName= EmpName  FROM Emp WHERE EmpId=@EmpId

end

---------------------Call Proc with output Parameter------------

DECLARE @EmpName varchar(30)

exec Usp_OutPutEmp 1,@EmpName output

print @EmpName

How to remove dublicate record in a table

 DELETE P1 FROM ProductId AS P1

INNER JOIN PRODUCTID AS P2 ON

P1.ProductId>P2.ProductId AND P1.PName=P2.PName