Date is not getting set - mysql

Question

I have a procedure that should always set a date, but it does not:
CREATE PROCEDURE 'player_extend_membership` (pid INTEGER, daysToAdd INTEGER, OUT result INTEGER)
BEGIN
SELECT PlayerMembershipEndDate INTO #memDate FROM players WHERE players.PlayerID = pid LIMIT 1;
SELECT ROW_COUNT() INTO #num;
IF #num = 0 THEN
SET result = -1;
ELSE
IF #memDate = NULL OR DATE(#memDate) < DATE(NOW()) THEN
SET #finalDate = DATE_ADD(DATE(NOW()), INTERVAL daysToAdd DAY);
ELSE
SET #finalDate = DATE_ADD(DATE(#memDate), INTERVAL daysToAdd DAY);
END IF;
SELECT #finalDate, #memDate;
UPDATE players SET PlayerMembershipEndDate = #finalDate
WHERE players.PlayerID = pid;
SET result = 1;
END IF;
END
When I check the return value, it is 1, therefore the account does exist. It tells me the result of the select query is always that #finalDate is NULL.
However, if ake it out of the IF and just do:
SET #finalDate = DATE_ADD(DATE(NOW()), INTERVAL daysToAdd DAY);
The date is set correctly.
I'm not sire what I am doing wrong.
Thanks

Answer 1

Your procedure seems way too complicated. Perhaps this does what you want:
set #result = -1;
UPDATE players
SET PlayerMembershipEndDate = (case when (#result := 1) is null then NULL
when #memDate IS NULL OR DATE(#memDate) < DATE(NOW())
then DATE_ADD(DATE(NOW()), INTERVAL daysToAdd DAY)
else DATE_ADD(DATE(#memDate), INTERVAL daysToAdd DAY)
end)
WHERE players.PlayerID = pid;
The first condition in the case just sets #result if a row is found. I've left your formulation of DATE(NOW()) even though CURDATE() is more succinct.
I suspect the actual problem with your logic was the = NULL. This always returns "UNKNOWN", which is treated as false. The correct expression is is NULL.