创建用户

//允许本地ip访问数据库的用户
create user 'test1'@'localhost' identified by '123';
//所有的ip都可以访问数据库的用户
create user 'test2'@'%' identified by '123';

刷新授权

flush privileges;

新建用户并赋予数据库所有权限(其中%代表登录用户的ip不限  localhost只能本地)

//授予指定数据库的所有权限
grant all privileges on `test_db`.* to 'test3'@'%' identified by '123' with grant option;
//授予指定数据库部分权限
grant select,update on demoDB.* to demo@'%' identified by '1234';
//授予所有数据库部分权限
grant select,delete,update,create,drop on *.* to demo@"%" identified by "1234";
//授予所有数据库所有权限
grant all privileges on *.* to demo@"%" identified by "1234";

修改指定用户的密码

mysql>update mysql.user set password=password('新密码') where User="demo" and Host="localhost";
mysql>flush privileges;

删除用户

mysql>Delete FROM user Where User='demo' and Host='localhost';
mysql>flush privileges;
mysql>drop database demoDB; //删除用户的数据库
删除账户及权限:>drop user 用户名@'%';
        >drop user 用户名@ localhost;