mysql创建触发器，同时修改两个表的内容为什么出错

代码如下
CREATE TRIGGER s_u AFTER INSERT ON cut_usual_message
FOR EACH ROW
UPDATE washer
SET washer.salary=washer.salary+new.cost
WHERE washer.washer_id=new.washer_id
UPDATE cutor
SET cutor.salary=cutor.salary+new.cost
WHERE cutor.cutor_id=new.cutor_id;
报错
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 'UPDATE cutor
SET cutor.salary=cutor.salary+new.cost
而如果仅UPDATE washer或UPDATE cutor都是正常的，如果顺序颠倒又报1054 - Unknown column 'new.washer_id' in 'where clause'的错，我应该怎么写呢？

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