You used
RETURN
statement without any value. If no value is specified on RETURN, a stored procedure returns the value 0.
Source:
Using RETURN[
^]
I would suggest you to read this article:
Return Data from a Stored Procedure[
^]. There are 2 ways to return data from SP.
Another way is to return recordset:
ALTER PROCEDURE bcSymbol
@bc decimal(18,15)
AS
BEGIN
SELECT fileSymbol
FROM fileNameGenerator
WHERE bc = @bc
END