How to solve the problem that golang cannot connect to mysql

As Golang continues to grow and develop in recent years, more and more developers are turning to Golang, a powerful language. However, when using Golang, some people encounter problems with being unable to connect to the MySQL database. This article will guide you on how to solve this problem.

Problem description:

When using Golang, sometimes there will be a problem of being unable to connect to the MySQL database. There are various reasons for this problem, such as the MySQL service is not started, there are problems with MySQL configuration, and the use of Golang's MySQL package is not standardized, etc.

Solution:

1. Confirm whether the MySQL service is started

First, rule out the possibility that the MySQL service is not started. Open a terminal and enter the command sudo systemctl status mysql to determine whether the MySQL service is started.

If the MySQL service has been started, there may be a problem with the MySQL configuration. You need to check whether the parameters in the MySQL client configuration file my.cnf and the MySQL server configuration file my.ini are correct.

2. Check whether the MySQL configuration parameters are correct

In my.cnf or my.ini, ensure that the following parameters are configured correctly:

[client]
port=<MySQL服务端口号>
user=<连接MySQL所需用户名称>
password=<连接MySQL所需密码>
default-character-set=utf8mb4

[mysql]
default-character-set=utf8mb4

[mysqld]
port=<MySQL服务端口号>
character-set-server=utf8mb4

Make sure yourself The MySQL service port number is correct, and the user name and password required by the MySQL client are also correct. In addition, ensure that the default character set of the MySQL server is set to utf8mb4 to support Chinese characters.

3. Using MySQL in Golang

When using the MySQL connector in Golang, you need to pay attention to the following:

• Import the correct MySQL library , execute the command go get -u github.com/go-sql-driver/mysql to import.

• Use the correct MySQL connection string, the sample code is as follows:

  func connect() *sql.DB {
    dbDSN := "你的MySQL连接字符串"
    db, err := sql.Open("mysql", dbDSN)
    if err != nil {
        panic("无法连接MySQL： " + err.Error())
    }
    if err = db.Ping(); err != nil {
        panic("无法ping通MySQL： " + err.Error())
    }
    fmt.Println("MySQL已连接！")
    return db
  }

In the above code, Your MySQL connection string should be replaced with your MySQL connection information.

4. Check network problems

If none of the above methods can solve the problem, there may be a problem with the Golang code itself or a network problem. You can use other MySQL client tools (such as HeidiSQL, Navicat, etc.) to test whether the MySQL service is normal. If the MySQL service is normal, you need to check whether there is a problem with the Golang code.

5. Other possibilities

If none of the above works, it may be that the MySQL version is too low or the special characters are garbled. At this time, it is recommended to go to the MySQL official forum or Github to find solutions to related problems.

Summary:

When using Golang to connect to MySQL, there are many possibilities of being unable to connect to the database, and we need to troubleshoot them one by one. Although you may feel a headache when encountering these problems, by carefully checking whether the MySQL service is started, checking whether the MySQL configuration parameters are correct, checking the use of MySQL in Golang and other steps to solve the problem, we can gain lasting accumulation and learn more about Golang connects the knowledge of MySQL to further improve the development level of Golang.

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