retain old value while update data in sql

Question

Hi!

any one has idea about this 

retain old value while update data in sql when parameters value is null or empty using procedure?

 

ALTER PROCEDURE [dbo].[sp_UpdateRatesForSubscriberByUtilityIfUserNameNull]

@address_id int ,

@FirstName nvarchar(100) ,

@LastName nvarchar(100) ,

@Address1 nvarchar(512) ,

@City nvarchar(256) ,

@State nvarchar(100) ,

@Zip nvarchar(50) ,

@PublicationID int ,

@RateID int ,

@ExpiryDate datetime ,

@SubscriberID int ,

@Phone nvarchar(250) ,

@Email nvarchar(250) ,

@Result int OUTPUT

AS

BEGIN

SET @Result = 0

Declare @Count int

Select @Count= Count(*) from Subscriber where SubscriberID= @SubscriberID

if(@Count>0)

begin

UPDATE Subscriber

SET address_id = @address_id,

Firstname = @FirstName,

Lastname = @LastName,

Address = @Address1,

City = @City,

State = @State,

Zip = @Zip,

ExpireDate = @ExpiryDate,

Rate_ID = @RateID,

Phone1 = @Phone,

Email = @Email

WHERE SubscriberID = @SubscriberID

AND (@address_id IS NOT NULL or @address_id!=''

OR @Firstname IS NOT NULL OR @Firstname!=''

OR @Lastname IS NOT NULL OR @Lastname!=''

OR @Address1 IS NOT NULL OR @Address1!=''

OR @City IS NOT NULL OR @City!=''

OR @State IS NOT NULL OR @State!=''

OR @Zip IS NOT NULL OR @Zip!=''

OR @ExpiryDate IS NOT NULL OR @ExpiryDate !=''

OR @RateID IS NOT NULL OR @RateID!=''

OR @Phone IS NOT NULL OR @Phone!=''

OR @Email IS Not NULL OR @Email !=''

) ;

UPDATE Payment Set SubscriptionExpiryDate=@ExpiryDate where SubscriberID=@SubscriberID and PublicationID=@PublicationID

UPDATE FreeSubscription Set RequestExpireDate=@ExpiryDate where SubscriberID=@SubscriberID and PublicationID=@PublicationID

AND (@ExpiryDate IS NOT NULL);

IF (@@ERROR <> 0)

BEGIN

SET @Result = -3 -- subscriber details not update in Subscriber table

END

End

Else

Begin

Set @Result=-3

End

RETURN @Result

END