Stored procedure parameters using tsql functions?

Question

Environment sql server 2005 sp3

I have a stored proc that takes an INT as input. I want to CAST a CHAR to an INT during the call to the stored proc. it seems I cannot do that. I get a syntax error before @foo. I do not see it can someone help me find it please. Thank you very much.

CREATE PROCEDURE testme
@test AS INT
AS
BEGIN
SELECT @TEST
END

    DECLARE @foo AS CHAR(6)
set @foo = '11test'
EXEC testMe @test = CAST(Substring(@foo,1,2) as int)

Answer 1

SQL Rockstar's answer is how to fix it: I'll add an explanation.

A stored procedure parameter can be either a constant or variable: not an expression. CAST is an expression. (This is different to udf parameters that can accept expressions)

EXEC on MSDN states

... @parameter = ] { value | @variable [ OUTPUT ] | [ DEFAULT ] }

Answer 2

Why not do the CAST when you SET @foo instead?

SET @foo = CAST(Substring('11test',1,2) as int)

You could even use a second variable and do this:

SET @foo1 = '11test'
SET @foo2 = CAST(Substring(@foo1,1,2) as int)

and then just call the proc:

EXEC testMe @test = @foo2