DataGrip连接MySQL出现Connection refused错误，请求技术协助

问题信息 #

连接错误提示：

DBMS: MySQL (no ver.)
Case sensitivity: plain=mixed, delimited=exact
Connection refused: connect.

idea.log关键日志片段：

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
2023-08-15 18:14:29,862 [ 139990]   INFO - #c.i.d.d.DatabaseConnectionEstablisher - Connecting to: jdbc:mysql://localhost:3306
2023-08-15 18:14:29,862 [ 139990]   INFO - #c.i.d.d.DatabaseConnectionEstablisher - Auth provider: user-pass
2023-08-15 18:14:29,863 [ 139991]   INFO - #c.i.d.d.DatabaseCredentialsAuthProvider - Connecting as: root
2023-08-15 18:14:29,869 [ 139997]   WARN - #c.i.d.d.DatabaseConnectionEstablisher - Connecting to: jdbc:mysql://localhost:3306
2023-08-15 18:14:29,869 [ 139997]   WARN - #c.i.d.d.DatabaseConnectionEstablisher - [08S01] Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

解决步骤 #

• 检查MySQL服务是否运行

  • Windows：打开「服务」面板，找到MySQL服务确认状态为「正在运行」；未运行则右键启动，或执行命令 net start mysql
  • Linux/macOS：执行命令 systemctl status mysql 查看状态，未运行则执行 systemctl start mysql 启动服务

• 验证连接地址与端口正确性

  • 确认DataGrip连接配置中URL为 jdbc:mysql://localhost:3306，检查MySQL配置文件（my.cnf/my.ini）：
    • port 参数是否设置为3306
    • bind-address 本地连接时设为127.0.0.1或localhost，需远程连接则设为0.0.0.0（允许所有IP访问）

• 检查MySQL用户权限

  • 登录MySQL客户端：mysql -u root -p
  • 执行查询查看用户权限范围：SELECT host, user FROM mysql.user;
  • 若root用户的host不是localhost或%，执行权限修改命令：
    • 本地连接：ALTER USER 'root'@'localhost' IDENTIFIED BY '你的密码';
    • 远程连接：ALTER USER 'root'@'%' IDENTIFIED BY '你的密码';
  • 刷新权限生效：FLUSH PRIVILEGES;

• 排查防火墙/安全软件拦截

  • Windows：临时关闭Windows防火墙测试，或添加3306端口的入站允许规则
  • Linux：执行 ufw allow 3306（Ubuntu/Debian）或 firewall-cmd --add-port=3306/tcp --permanent && firewall-cmd --reload（CentOS/RHEL）

• 匹配MySQL驱动版本

  • 在DataGrip连接设置的「驱动」选项卡中，确认驱动版本与MySQL服务器版本匹配：MySQL 8.0+使用8.x版本驱动，5.7及以下使用5.x版本驱动，可直接在DataGrip内点击「下载」更新驱动

内容的提问来源于stack exchange，提问作者mmt