mysql> show databases; //显示所有数据库
+--------------------+ 
| Database |
+--------------------+ 
| information_schema | 
| mysql | 
| performance_schema | 
| test | 
+--------------------+ 
4 rows in set (0.00 sec) 

mysql> use mysql; 
Database changed 
mysql> delete from user where user=''; 
Query OK, 1 row affected (0.00 sec) 

mysql> update User set Password=PASSWORD('123456') where User='root';
Query OK, 4 rows affected (0.00 sec) 
Rows matched: 4 Changed: 4 Warnings: 0 
mysql> flush privileges; 
Query OK, 0 rows affected (0.00 sec) 

D:\mysql-5_x64\bin>mysql -u root -p //用root用户登入数据库 
Enter password: ******  //输入更新后的密码 123456 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 5 
Server version: 5.6.26 MySQL Community Server (GPL) 
Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved. 
Oracle is a registered trademark of Oracle Corporation and/or its 
affiliates. Other names may be trademarks of their respective 
owners. 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. 
mysql> 

mysql> grant all privileges on *.* to 'root'@'192.168.1.%' identified by 'root' with grant option; 
Query OK, 0 rows affected (0.00 sec) 
mysql> flush privileges; 
Query OK, 0 rows affected (0.00 sec) 
mysql> select host,user,password from user;
+-------------+------+-------------------------------------------+
| host | user | password  |
+-------------+------+-------------------------------------------+
| 192.168.1.% | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
+-------------+------+-------------------------------------------+
4 rows in set (0.00 sec)