Passing sets and optional parameters to a stored procedure T-SQL - ASP.NET

You can achieve optional parameters in T-SQL stored procedures by having default values equal NULL.

Example where NULL is used as "ignore this parameter":

CREATE PROCEDURE [dbo].[dcspFilterEmpList]
    @ProductName nvarchar(200) = null,
    @ProductGroupID int = null
AS BEGIN 

    SELECT
    prod_id AS 'ID',
    prod_name AS 'Name'
    FROM dbo.Products

    WHERE (prod_group_id = @ProductGroupID OR @ProductGroupID IS NULL)
    AND (prod_name = @ProductName OR @ProductName IS NULL)

END

It's perfectly fine to define a stored procedure to take a table-valued parameter in T-SQL. Here is an article on the subject http://sqlwithmanoj.wordpress.com/2012/09/10/passing-multipledynamic-values-to-stored-procedures-functions-part4-by-using-tvp/

If you need more info on this google for "table-valued parameter"

Example using multi-valued parameters:

CREATE TYPE XTV_ProductNames AS TABLE  --extension, table valued == XTV
( ProductName nvarchar(50))
GO
CREATE TYPE XTV_ProductGroups AS TABLE  --extension, table valued == XTV
( ProductGroupID int))
GO
CREATE PROCEDURE [dbo].[dcspFilterEmpList]
    @TVP1 XTV_ProductNames READONLY
    ,@TVP2 XTV_ProductGroups READONLY
AS BEGIN 
    SELECT
    prod_id AS 'ID',
    prod_name AS 'Name'
    FROM dbo.Products as p
    INNER JOIN @TVP1 as s
        ON p.prod_name = s.ProductName
    UNION
    SELECT
    prod_id AS 'ID',
    prod_name AS 'Name'
    FROM dbo.Products as p
    INNER JOIN @TVP2 as s
        ON p.prod_group_id = s.ProductGroupID
END

Your answer was correct David, but it was a little misleading because the parameter equaling NULL does not make it optional; it just has to be set to any value period. This also creates optional parameters:

CREATE PROCEDURE [dbo].[dcspFilterEmpList]
    @ProductName nvarchar(200) = 'DefaultProduct',
    @ProductGroupID int = 1
AS

Which could thus be executed without passing any parameters, i.e.:

EXEC [dbo].[dcspFilterEmpList]

I understand that this wasn't necessarily what Piscovetz was trying to do, but it seems to match more closely the actual topic question shown, and it is an important distinction.