mysql -u root -p

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 6

Server version: 5.6.23-log Source distribution

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> use mysql;

Database changed

mysql> select host,user,password from user;

+———–+——+——————————————-+

| host | user | password |

+———–+——+——————————————-+

| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| 127.0.0.1 | root | |

| ::1 | root | |

| localhost | | |

+———–+——+——————————————-+

4 rows in set (0.00 sec)

mysql> update user set host=’%’ where user=’root’;

ERROR 1062 (23000): Duplicate entry ‘%-root’ for key ‘PRIMARY’

mysql> update user set host=’ %’ where user=’root’;

ERROR 1062 (23000): Duplicate entry ’ %-root’ for key ‘PRIMARY’

mysql> select host,user from user where user=’root’;

+———–+——+

| host | user |

+———–+——+

| % | root |

| 127.0.0.1 | root |

| ::1 | root |

+———–+——+

3 rows in set (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.02 sec)

mysql> quit;

Bye

./etc/init.d/mysql restart

Shutting down MySQL. [ OK ]

Starting MySQL. [ OK ]

mysql -u root -p

ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: Y

ES)

mysql -u root -p

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 6

Server version: 5.6.23-log Source distribution

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> exit;

Bye

mysqladmin -uroot password 123456

mysql -uroot -p123456

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 6

Server version: 5.6.23-log Source distribution

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> grant all privileges on . to ‘root’@’%’ identified by ‘123456’ with gra

nt option;

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

解释下上面遇到的问题：

1.首先查询有没有开启远程访问（可以让任意IP通过root用户访问）

2.没有开启，则修改host=’%’，会报错：ERROR 1062 (23000): Duplicateentry ’ %-root’for key’PRIMARY’

3.忽略第二个问题，并flush privileges;（刷新MySQL系统权限相关表，否则会报错：拒绝访问）

4.通过命令重新登录报错：ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: YES)，原因是密码变成空了，重新设置密码：mysqladmin -uroot password 123456

5.这个时候访问还是报错： host ip is not allowed to connect to this mysql。通过以下两个命令即可解决，grant all privileges on . to ‘root’@’%’ identified by ‘123456’ with grant option;flush privileges;