来源：http://hi.baidu.com/loveyurui/blog/item/1c657ac9131b9a15bf09e67d.html
+----+------+------+ | Id | sal | num | +----+------+------+ | 13 | 600 | 10 | | 14 | 200 | 10 | | 15 | 300 | 10 | +----+------+------+
写好的MySQL触发器 如下：
CREATE TRIGGER ins_trig before insert ON hello.yy FOR EACH ROW BEGIN update yy set sal=sal+100 where num>10 END;
这个触发器是可以执行成功的 然后我们测试(激活)
insert into yy values(0,2000,11);
理论上按照触发器的定义插入的值应该为16 2100 11 可是令人郁闷的错误出现了：
ERROR 1442 (HY000): Can't update table 'yy' in stored function/trigger because i t is already used by statement which invoked this stored function/trigger.
网上找遍了所有的解决办法 最后在国外的一个帖子上找到了solution
将触发器定义改成如下：
CREATE TRIGGER ins_trig before insert ON hello.yy FOR EACH ROW BEGIN if new.num>10 then set new.sal = new.sal + 100; end if; END;
然后插入刚才的测试值就ok了
mysql> insert into yy values(0,2000,11); Query OK, 1 row affected (0.01 sec)
mysql> select * from yy; +----+------+------+ | Id | sal | num | +----+------+------+ | 13 | 600 | 10 | | 14 | 200 | 10 | | 15 | 300 | 10 | | 16 | 2100 | 11 | +----+------+------+ 5 rows in set (0.00 sec)
原帖连接为：http://crazytoon.com/2008/03/03/mysql-error-1442-hy000-cant- update-table-t1-in-stored-functiontrigger-because-it-is-already-used-by-statement-which-invoked-this-stored-functiontrigger/
