连接远程mysql数据库失败常见原因及解决办法

安装好mysql后，想本地用Navicat直接远程链接方便一些，结果发现连不上。我第一个想到的就是数据库没有开放远程登陆权限，于是设置明明如下：

1.进入mysql开放权限

bash-4.2# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 399
Server version: 5.7.29 MySQL Community Server (GPL)

Copyright (c) 2000, 2020, 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, 1 warning (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

再次链接，又是一样的错误！！！如图：

查看网络端口开放情况：

[root@docker home]# ss -tlnp
State       Recv-Q Send-Q        Local Address:Port                       Peer Address:Port              
LISTEN      0      100               127.0.0.1:25                                    *:*                   users:(("master",pid=1554,fd=13))
LISTEN      0      128                       *:22                                    *:*                   users:(("sshd",pid=1161,fd=3))
LISTEN      0      100                   [::1]:25                                 [::]:*                   users:(("master",pid=1554,fd=14))
LISTEN      0      128                    [::]:22                                 [::]:*                   users:(("sshd",pid=1161,fd=4))

果然没有数据3306的端口，也就是说服务器不允许非本地ip访问数据库。

新建用户
CREATE USER ‘data_center’@‘%’ IDENTIFIED BY ‘pass’;

GRANT ALL PRIVILEGES ON . TO ‘data_center’@‘%’ WITH GRANT OPTION;

ALTER USER ‘data_center’@‘%’ IDENTIFIED WITH mysql_native_password BY ‘pass’;

2.配置文件限制远程访问。

可能是配置文件只允许自己本机才能访问，所以就去修改配置文件：
找到

bind-address = 127.0.0.1
或
skip-networking

并注释掉，然后重启mysql。