查询所有用户：select user from mysql.user;
创建用户：CREATE USER ‘username’@‘%’ IDENTIFIED BY ‘userpwd’;
修改密码：update mysql.user set password=password(‘新密码’) where user=‘username’;
创建数据库：create database test_a
查看创建的数据库：show create database test_a
给用户授权：grant all privileges on 数据库名.* to ‘user1’@‘%’;
刷新权限：flush privileges;
查看引擎：
show engines;