Question

I am trying to create a stored procedure that has optional parameters. I followed the instructions listed here. I also referenced this SO question. However I keep receiving the following error:

Error converting data type varchar to int.

It works when I execute it as

EXEC sp_get_user {id#}

or

EXEC sp_get_user NULL, {username}

but fails with

EXEC sp_get_user {username}

Stored Procedure

@id int = NULL,
@username nvarchar(50) = NULL

SELECT
    username = COALESCE(a.Username, b.Username),
    password = COALESCE(a.Password, b.Password),
    signup_date = COALESCE(a.SignedUpOn, b.Signup_Date)
FROM table1 a
FULL OUTER JOIN table 2 b
ON a.ID = b.ID
WHERE ((a.ID = @id OR @id IS NULL)
AND (a.Username = @username OR @username IS NULL)
OR (b.ID = @id OR @id IS NULL)
AND (b.Username = @username OR @username IS NULL))

I have tried adding the OPTION(RECOMPILE) and had no success. I want to make this dynamic so other developers can call this SP without having to specify all parameters each time. They will be connecting via LINQ if that makes a difference.

Answer 1

use named parameters in that case

EXEC sp_get_user @username = {username}

if both parameters are optional, SQL server will go by position, so the first one you are passing in will map to the first one in the proc