multi cursor stored procedure in teradata - sql

Question

I am completely new to sql and teradata(6weeks). and have been given an assignment, which had little instruction.
(Create a stored procedure that allows a user to select a bat’s manufacturer and (optionally) serial number using a stored procedure. The output should display all of the players who use the bat’s manufacturer. If the serial number is also provided, only display the players who use that bat’s manufacturer and serial number. Make sure you use a CREATE PROCEDURE call and insert this procedure into the existing database. ) this is a database through teradata that has been duplicated into my own database to be edited. This is what I got so far and it keeps returning two errors. I'd love help with a solution and best possible recommendation for learning sql quickly and efficiently. I appreciate the help in advance. and i'm sure this is the ugliest code you've seen, I aplogize. :-D
CREATE PROCEDURE batman(manuf varchar(20), bat_type varchar(4)=null)
DYNAMIC RESULT SETS 2
BEGIN
DECLARE c CURSOR FOR
SELECT playernum
FROM affiliation, bats
WHERE manuf = :manuf;
declare serial cursor for
select playernum
from affiliation
where bat_type=NULL or bat_type=:bat_type
if bat_type=NULL then open c
else open serial;
end if;
END;

Answer 1

The default of a parameter is always NULL, no need to declare that.
You can't compare NULLs using =, must be is null instead.
And there are some missing semicolons...
CREATE PROCEDURE batman(manuf VARCHAR(20), bat_type VARCHAR(4))
DYNAMIC RESULT SETS 1
BEGIN
DECLARE c CURSOR FOR
SELECT playernum
FROM affiliation, bats
WHERE manuf = :manuf;
DECLARE serial CURSOR FOR
SELECT playernum
FROM affiliation
WHERE bat_type IS NULL OR bat_type=:bat_type;
IF bat_type IS NULL THEN OPEN c;
ELSE OPEN serial;
end if;
END;