1、[Err] 1442 - Can't update table 't_teacher' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. You cannot change a table while the INSERT trigger is firing. The INSERT might do some locking which could result in a deadlock. Also, updating the table from a trigger would then cause the same trigger to fire again in an infinite recursive loop. Both of these reasons are why MySQL prevents you from doing this. However, depending on what you're trying to achieve, you can access the new values by using NEW.fieldname or even the old values--if doing an UPDATE--with OLD. If you had a row named full_brand_name and you wanted to use the first two letters as a short name in the field small_name you could use: CREATE TRIGGER `capital` BEFORE INSERT ON `brandnames` FOR EACH ROW BEGIN SET NEW.short_name = CONCAT(UCASE(LEFT(NEW.full_name,1)) , LCASE(SUBSTRING(NEW.full_name,2))) END 2、报错:1130-host ... is not allowed to connect to this MySql server 开放mysql远程连接 不使用localhost 报错:1130-host ... is not allowed to connect to this MySql server 解决方法： 1. 改表法。 可能是你的帐号不允许从远程登陆，只能在localhost。这个时候只要在localhost的那台电脑，登入mysql后，更改 "mysql" 数据库里的 "user" 表里的 "host" 项，从"localhost"改称"%" mysql -u root -pvmwaremysql>use mysql; mysql>update user set host = '%' where user = 'root'; mysql>select host, user from user; 2. 授权法。 例如，你想myuser使用mypassword从任何主机连接到mysql服务器的话。 GRANT ALL PRIVILEGES ON *.* TO 'myuser'@'%' IDENTIFIED BY 'mypassword' WITH GRANT OPTION; FLUSH PRIVILEGES; 如果你想允许用户myuser从ip为192.168.1.6的主机连接到mysql服务器，并使用mypassword作为密码 GRANT ALL PRIVILEGES ON *.* TO 'myuser'@'192.168.1.3' IDENTIFIED BY 'mypassword' WITH GRANT OPTION; FLUSH PRIVILEGES; 如果你想允许用户myuser从ip为192.168.1.6的主机连接到mysql服务器的dk数据库，并使用mypassword作为密码 GRANT ALL PRIVILEGES ON dk.* TO 'myuser'@'192.168.1.3' IDENTIFIED BY 'mypassword' WITH GRANT OPTION; FLUSH PRIVILEGES; 我用的第一个方法,刚开始发现不行,在网上查了一下,少执行一个语句 mysql>FLUSH RIVILEGES 使修改生效.就可以了 另外一种方法,不过我没有亲自试过的,在csdn.net上找的,可以看一下. 在安装mysql的机器上运行： 1）d:\mysql\bin\>mysql -h localhost -u root //这样应该可以进入MySQL服务器 2）mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION //赋予任何主机访问数据的权限 3）mysql>FLUSH PRIVILEGES //修改生效 4）mysql>EXIT //退出MySQL服务器 这样就可以在其它任何的主机上以root身份登录啦！