Passing Table to a Function Parameter in SQL Server 2012

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('Rohatash')
SELECT dbo.StudentDetailFunction(@StudentVariable)

Output