如何解决这个IF-ELSE-THEN语句在MySQL触发

Question

可能重复：
How to fix this MySQL trigger?

CREATE TRIGGER Transaction_insert BEFORE INSERT ON Transaction 
FOR EACH ROW 
IF Account.CreditBalance + NEW.Amount < Account.CreditLimit WHERE Number = NEW.AccountNumber THEN 
UPDATE Account SET CreditBalance = CreditBalance + NEW.Amount where Number = NEW.AccountNumber; 
ELSE 
SET NEW.Valid = 0 
END IF; 

我从phpMyAdmin的此错误消息。

Answer 1

这是If语句的语法正确。

IF search_condition THEN statement_list 
    [ELSEIF search_condition THEN statement_list] ... 
    [ELSE statement_list] 
END IF 

您不能在该位置拥有Where子句！