MySQL 8.x 账号管理

MySQL 8.x 和MySQL 5.x 创建账号不太一样，MySQL 8 开始不允许用grant带密码创建账号了，要先创建账号再设置权限

MySQL 8.x

# 创建账号
create user "root"@"%" identified by "xxx";
# 授权
grant all privileges on *.* to "root"@"%" with grant option;（执行该命令也可以直接创建账号）
# 刷新权限
flush privileges;
# 修改密码加密方式（MySQL 8 默认用 caching_sha2_password 插件加密密码）
alter user root identified with mysql_native_password by "xxx";
或者
update mysql.user set plugin="mysql_native_password" where user="root";

MySQL 5.x

# 创建账号并授权
grant all privileges on *.* to root@"%" identified by "xxx";

下面以test账号为例，记录常用命令（在MySQL 8.0.25操作）

授权test用户拥有所有数据库的某些权限

create user "test"@"localhost" identified by "xxx";
grant select,delete,update,create,drop on *.* to test@"localhost";

修改指定用户密码

alter user "test"@"localhost" identified by "123";
# 指定密码认证插件
alter user "test"@"localhost" identified with mysql_native_password by "123";
# 设置密码后，记得刷新权限
flush privileges;
或者
mysqladmin -u root -p password 123
回车之后会要求让输入原始密码
# 注意，不能用以下SQL修改密码，原因：MySQL 5.7.9 之后取消了password 函数，authentication_string=password("xxx") 会报错
update mysql.user set authentication_string=password("xxx") where user="test" and host="localhost"; 

删除用户

delete from mysql.user where user="test" and host="localhost";
或者
drop user "test"@"localhost";

查看权限

# 查看当前用户权限
show grants;
# 查看其他 MySQL 用户权限
show grants for "test"@localhost;

撤销已经赋予给 MySQL 用户权限的权限

revoke 跟 grant 的语法差不多，只需要把关键字 to 换成 from 即可： 

grant all on *.* to "test"@"localhost";
revoke all on *.* from "test"@"localhost";