MySQL中基本的用户和权限管理方法小结_MySQL
MySQL 默认有个root用户,但是这个用户权限太大,一般只在管理数据库时候才用。如果在项目中要连接 MySQL 数据库,则建议新建一个权限较小的用户来连接。
在 MySQL 命令行模式下输入如下命令可以为 MySQL 创建一个新用户:
CREATE USER username IDENTIFIED BY 'password';
新用户创建完成,但是此刻如果以此用户登陆的话,会报错,因为我们还没有为这个用户分配相应权限,分配权限的命令如下:
GRANT ALL PRIVILEGES ON *.* TO 'username'@'localhost' IDENTIFIED BY 'password';
授予username用户在所有数据库上的所有权限。
如果此时发现刚刚给的权限太大了,如果我们只是想授予它在某个数据库上的权限,那么需要切换到root 用户撤销刚才的权限,重新授权:
EVOKE ALL PRIVILEGES ON *.* FROM 'username'@'localhost'; GRANT ALL PRIVILEGES ON wordpress.* TO 'username'@'localhost' IDENTIFIED BY 'password';
甚至还可以指定该用户只能执行 select 和 update 命令:
GRANT SELECT, UPDATE ON wordpress.* TO 'username'@'localhost' IDENTIFIED BY 'password';
这样一来,再次以username登陆 MySQL,只有wordpress数据库是对其可见的,并且如果你只授权它select权限,那么它就不能执行delete 语句。
另外每当调整权限后,通常需要执行以下语句刷新权限:
FLUSH PRIVILEGES;
删除刚才创建的用户:
DROP USER username@localhost;
仔细上面几个命令,可以发现不管是授权,还是撤销授权,都要指定响应的host(即 @ 符号后面的内容),因为以上及格命令实际上都是在操作mysql 数据库中的user表,可以用如下命令查看相应用户及对应的host:
SELECT User, Host FROM user;
当然,这个表中还包含很多其它例如用户密码、权限设置等很多内容,操作时候尤其需要小心。

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