SQL SERVER CURSORS

CURSORS : - In Simple words, Cursor is a database object used by applications to manipulate data in a set on a row-by-row basis,

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-- SINGLE  VARIABLE AS INPUT TO EXEC PROCEDURE which takes only one variable as input

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DECLARE @CLIENTKEY INT           

DECLARE CLIENTKEYCURSOR CURSOR

              FOR SELECT ID FROM customer 

OPEN CLIENTKEYCURSOR                                    -- open cursor

                                                       -- DO SOMETHING USEFUL

       FETCH NEXT FROM CLIENTKEYCURSOR                 -- fetch record

       INTO @CLIENTKEY

       WHILE @@FETCH_STATUS = 0

              BEGIN 

                     FETCH NEXT FROM CLIENTKEYCURSOR   -- loop through every record

                           INTO @CLIENTKEY

                           EXEC dbo.uspUpdateClientDate @CLIENTKEY

                           --SELECT   @CLIENTKEY

               END         

CLOSE CLIENTKEYCURSOR                                  -- close cursor

DEALLOCATE CLIENTKEYCURSOR                             -- deallocate cursor

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---- MORE THAN ONE VARIABLE AS INPUT TO EXEC PROCEDURE which takes three variable as input

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DECLARE @ID INT,@NAME VARCHAR(100), @AD VARCHAR(100)

DECLARE  NAMECURSOR CURSOR

               FOR SELECT ID, NAME, [ADD] FROM CUSTOMER

OPEN NAMECURSOR

              FETCH NEXT FROM NAMECURSOR

                     INTO @ID, @NAME, @AD

       WHILE @@FETCH_STATUS = 0

       BEGIN

              FETCH NEXT FROM NAMECURSOR

                     INTO @ID, @NAME, @AD

           EXEC [dbo].[UspInsertCustomerDetails] @ID, @NAME, @AD

       END

CLOSE NAMECURSOR

DEALLOCATE NAMECURSOR