1、防火墙问题：

说明：使用telnet命令连接不通mariadb服务器端口

解决方案：

为防火墙添加开放端口命令：firewall-cmd --zone=public --add-port=3306/tcp --permanent

重新载入命令：firewall-cmd --reload

然后问题解决。

2、Could not connect to address=(host=192.168.90.3)(port=3306)(type=master) : (conn=4) Access denied for user 'root'@'gateway' (using password: YES)
Current charset is GBK. If password has been set using other charset, consider using option 'passwordCharacterEncoding'
  (conn=4) Access denied for user 'root'@'gateway' (using password: YES)
Current charset is GBK. If password has been set using other charset, consider using option 'passwordCharacterEncoding'
  (conn=4) Access denied for user 'root'@'gateway' (using password: YES)
Current charset is GBK. If password has been set using other charset, consider using option 'passwordCharacterEncoding'

问题说明：这是对root用户的授权问题。

解决方案：grant all privileges on *.* to 'root'@'%' identified by 'root';

3、 SQL 错误 [1366] [22007]: (conn=5) Incorrect string value: '\xE5\x9B\x9B' for column 'area_cut' at row 1

问题说明：字符集问题

解决方案：修改字符集

step1:使用 whereis my.ini 查询配置文件路径

step2:添加配置信息

default-character-set=utf8
character-set-server=utf8

step3:重启服务

systemctl restart mariadb.service

如果还未解决，尝试重新建库，设置默认字符集

create database db_name default character set utf8;