In this article, I described how to pass a table to a function parameter in SQL Server. In this article, you create a table, student, then create a user-defined table type and pass the table type as a parameter to a function. So let's have a look at a practical example of how to pass a table as a function parameter in SQL Server. The example is developed in SQL Server 2012 using the SQL Server Management Studio.

Here is how to implement passing a user-defined table type to a function.

1. Create a Student Table in SQL Server
Create a table named Student.
CREATE TABLE [dbo].[Student] 
( 
    [StudentID] [int] NULL, 
    [StudentName] [varchar](30) NULL, 
    [StudentFees] [int] NULL 
) 

2. Create a User-Defined Table Type in SQL Server
Now create a user-defined table type to be used as a table-valued parameter in the function.
CREATE TYPE dbo.StudentType AS TABLE 
( 
   [StudentID] [int] , 
   [StudentName] [varchar](30) , 
   [StudentFees] [int]  
) 

Now Press F8 to see the created type in the Object Explorer.
Database->Programmability->Types->User Define Table Types

3. Creating a Function in SQL Server
Now create the StudentDetailFunctionFunction. This function will accept a table-valued parameter.
READONLY keyword - This keyword is required to declare a table-valued parameter.

ALTER FUNCTION StudentDetailFunction( @StudentDetail dbo.StudentType READONLY ) 
RETURNS VARCHAR(50) 
AS 
BEGIN 
    DECLARE @Studentname VARCHAR(50) 
    SELECT  @Studentname= StudentName FROM @StudentDetail 
    RETURN @Studentname 
END 

4. Execute the SQL Server Function
Now you can declare a variable @StudentVariable which contains the value of the table columns.
DECLARE @StudentVariable AS StudentType 
INSERT INTO @StudentVariable(StudentName) VALUES('Peter') 
SELECT dbo.StudentDetailFunction(@StudentVariable)