How to fix this MySQL trigger?

Question

I\'m trying to get this trigger to work:

CREATE TRIGGER Transaction_insert BEFORE INSERT ON Transaction
FOR EACH ROW WHERE Number = NEW.AccountNumber 
IF Account         


        

Answer 1

Your IF needs to be a full SELECT to reference another table (Account)

IF EXISTS (SELECT * FROM `Account` A
            WHERE A.CreditBalance + NEW.Amount < A.CreditLimit AND 
                   A.Number = NEW.AccountNumber) THEN
   UPDATE ...

Edit: this was on your 2nd duplicate answer

In this case, remove the WHERE after FOR EACH ROW