mysql安装和登录

use mysql;
mysql5.7可以使用：
update mysql.user set authentication_string=password('123456#Abc')  where user='root'
mysql 8使用：
update user set authentication_string='123456#Abc'  where  user='root';

insert into mysql.user(Host,User,authentication_string) values("localhost","test",password("123456"));

select user from user;