Question

I want the Update statement to be done when my bit parameter’s value is 1. How can this be achieved?

This is my stored procedure :

 CREATE PROCEDURE sp_subBalance @Cost decimal, @userid int, @bit bit output
 AS
    declare @SubbedBalance decimal, @Currbalance decimal

    set @Currbalance = (SELECT User_Balance_tbl.Balance
                        FROM User_Balance_tbl
                        WHERE User_Balance_tbl.UserID = @userid)

    set @SubbedBalance = (select @Currbalance - @cost)

    set @bit = (case when @SubbedBalance > 0 Or @SubbedBalance = 0 then 1 else 0 end) 

    case when @bit = 1 then (update User_Balance_tbl 
                             set Balance = @SubbedBalance  
                             where  User_Balance_tbl.UserID = @userid) 
end

Answer 1

It can be done below way:

 CREATE PROCEDURE sp_subBalance @Cost decimal , @userid int
 ,@bit bit output
 AS

 declare @SubbedBalance decimal
 , @Currbalance decimal

 set @Currbalance =
 (
 SELECT User_Balance_tbl.Balance
 FROM User_Balance_tbl
 WHERE User_Balance_tbl.UserID = @userid
 )
 set @SubbedBalance = (select @Currbalance - @cost)
 set @bit =( case when @SubbedBalance>0 Or @SubbedBalance=0  then 1 else 0 end) 

 IF (@bit=1)
   BEGIN
      update User_Balance_tbl set Balance = @SubbedBalance  
        where  User_Balance_tbl.UserID = @userid
   END