Conversion failed when converting the varchar value 'my returned value' to data type int

Question

I get this error in this simple SQL statement when trying to retrieve a string from a table.

Msg 245, Level 16, State 1, Procedure prViewRequirements, Line 18 Conversion

Answer 1

Try This:

alter procedure dbo.prViewRequirements
    @WFRouteID int
    , @DocumentDescription varchar(100) = null output
AS

BEGIN
select @DocumentDescription = '' -- Init

select @DocumentDescription = DocumentDescription
from tbFollowOnTracking
where WFRouteID = @WFRouteID
and IsActive = 1

END

Execute the proc as shown below

DECLARE @res varchar(100)
exec dbo.prViewRequirements @WFRouteID,@DocumentDescription=@res OUTPUT
select @res