How to call a SQL function with a Stored Procedure?
There are two types of functions in SQL Server. These are:
- System defined functions
- User-defined functions
Again, user-defined functions are also further classified into three types:
- Scalar function: These functions return a single value as a result of tasks executed by the function.
- Inline table-valued functions: A result in the form of a table is returned by these functions on execution.
- Multi-statement Table-valued functions: user-defined multi-statement table-valued function values are generated as a result of these functions being executed.
Here, we will show how we can call a function with the help of a stored procedure in SQL Server with the help of a simple example.
Let's take a scalar function named Fnctn which will take two integer values and return their product in a third integer value.
Creating a user-defined scalar function in SQL Server:
let us quickly create a function named Fnctn with two parameters num1 and num2 returning a result in another parameter named ‘res’.
Both the parameters are of the same data type .i.e. int.
The function is given below:
create function [dbo].[fnctn] ( @num1 int, @num2 int ) returns int as begin declare @res int select @res = @num1 * @num2; return @res end
creating a stored procedure in SQL Server
we can call a function using a select command or by using it in a stored procedure.
The function would return a value as a result, therefore we need a parameter in the stored procedure as well so as to hold the result value in it.
A stored procedure including a function in it is given below for an instance.
create procedure [dbo].[SP1] ( @p1 int, @p2 int ) as begin declare @pro int select [dbo].[fnctn](@p1 , @p2) end
we can call the function as :
select dbo.[fnctn](3,10) as fnctn
The result will be like:
the values 3 and 10 are passed in the two parameters which generate a result as 30 by using the function with a stored procedure.