mysql 触发器的新手问题.

表tab3 如果ID大于5,自动改为5,
Create table tab3(id int not null);
Create trigger inser_update_a
Before insert or update on tab3
FOR each ROW 
AS BEGIN 
IF tab3.id >5
then tab3.id= 5
end if
end ;
 上面有错吗, 我运行不出来,报错:
Error Code : 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 'or update on tab3
FOR each ROW 
AS BEGIN 
IF tab3.id >5
then tab3.id= 5
end if
e' at line 2


请问各位是怎么回事呢..

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Before insert or update on tab3

MySQL不支持这种语法，只能分开写。写两个触发器分别是

Create trigger inser_update_a_1 before insert ....

Create trigger inser_update_a_2 before update ....

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MySQL官方文档 http://dev.mysql.com/doc/refman/5.1/zh/index.html

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ACMAIN_CHM:
 你好,
我把update 删了,运行:
Create trigger inser_update_a
Before insert on tab3
FOR each ROW 
AS BEGIN 
IF tab3.id >5
then tab3.id= 5
end if
end ;
语法上应该没错,我是看了数据库系统概论里面的一个例子,再用本地的做下实验,但是还是报错:
Error Code : 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 'AS BEGIN 
IF tab3.id >5
then tab3.id= 5
end i