觸發器 - 語法錯誤＃1064新舊

Question

我在這裏犯了什麼錯誤？

CREATE TRIGGER total BEFORE UPDATE ON `current` FOR EACH ROW 
BEGIN 
if new.`new_pay_date` <> old.`new_pay_date` 
    SET new.`total_cash` = new.`curr_cash` + new.`total_cash`; 
end if; 
END; 
$$ 

錯誤：

#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 'SET new.`total_cash` = new.`curr_cash` + new.`total_cash`; end if;' at line 4 

這是工作不

if new.`new_pay_date` <> old.`new_pay_date` 
end if; 

但我需要檢查這一點，只有日期更改更新。

當前表：

curr_cash 
new_pay_date 
id_person 
id_thing 
total_cash 

任何人都可以幫助我嗎？

Answer 1

嘗試在if語句的末尾添加THEN：

IF new.`new_pay_date` <> old.`new_pay_date` THEN 
    SET new.`total_cash` = new.`curr_cash` + new.`total_cash`; 
END IF;