在其它电脑主机上访问时提示host ip is not allowed to connect to this mysql
下面代码为解决该问题的方法：
:\Program Files\mysql-5.5.51\bin>mysql -u root -p Enter password: ******
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.51-log MySQL Community Server (GPL)
Copyright (c) 2000, 2011, 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
D:\Program Files\mysql-5.5.51\bin>net stop MySQL
MySQL 服务正在停止.
MySQL 服务已成功停止。
D:\Program Files\mysql-5.5.51\bin>net start MySQL
MySQL 服务正在启动 .
MySQL 服务已经启动成功。
D:\Program Files\mysql-5.5.51\bin>mysql -u root -p
Enter password: ******
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: Y
ES)
D:\Program Files\mysql-5.5.51\bin>mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.51-log MySQL Community Server (GPL)
Copyright (c) 2000, 2011, 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
D:\Program Files\mysql-5.5.51\bin>mysqladmin -uroot password 123456
D:\Program Files\mysql-5.5.51\bin>mysql -uroot -p123456
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.5.51-log MySQL Community Server (GPL)
Copyright (c) 2000, 2011, 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 grant 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;
参考：https://jingyan.baidu.com/article/60ccbceb05804164cab1978c.html