How to declare a value in a trigger in mysql? - mysql

Question

I am trying to write a trigger for my database using mysql and phpmyadmin. I have a database with a table for a client's information in which I store a credit card number and a table for hotel reservations where I store the client's way of paying. I want my trigger to activate after update on client's info and if the credit card number is deleted to change the way of payment. The problem is that phpmyadmin does not compile it.
CREATE TRIGGER after_credit_card_update
AFTER UPDATE
ON client
for each row
BEGIN
declare cl_id int;
IF ( (new.Credit_Card_Number = " ") or (new.Credit_Card_Number is null)) then
select into cl_id
select reservation.Client_Id from
reservation where ((reservation.Client_Id = new.Client_Id) and (reservation.Payment = 'Credit'))
limit 1 ;
update reservation
set reservation.Payment = "NOT PAID"
where reservation.Client_Id = cl_id;
END IF;
END$$
I believe that the problem is when I am declaring my value: cl_id
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'into cl_id select reservation.Client_Id from reservation where ' at line 8
FIXED :
DELIMITER $$
CREATE TRIGGER after_credit_card_update
AFTER UPDATE
ON client
for each row
BEGIN
declare cl_id int;
IF ( (new.Credit_Card_Number = " ") or
new.Credit_Card_Number is null)) then
select reservation.Client_Id into cl_id from reservation
here ((reservation.Client_Id = new.Client_Id) and
reservation.Payment = 'credit'))
limit 1 ;
update reservation
set reservation.Payment = "NOT PAID"
where reservation.Client_Id = cl_id;
END IF;
END$$
DELIMITER ;

Answer 1

Not going into detail here, but you need to add delimiter statements before and after your trigger - so MySQL will know how to parse the code. For example:
DELIMITER $$
CREATE TRIGGER after_credit_card_update
AFTER UPDATE
ON client
for each row
BEGIN
declare cl_id int;
IF ( (new.Credit_Card_Number = " ") or
new.Credit_Card_Number is null)) then
select into cl_id
select reservation.Client_Id from
reservation where reservation.Client_Id = new.Client_Id
limit 1 ;
update reservation
set reservation.Payment = "NOT PAID"
where reservation.Client_Id = cl_id;
END IF;
END$$
DELIMITER ;