如何连接MySQL数据库？

Question

我是C#编程的新手,但希望能够访问MySQL数据库(没有MS SQL的钱)

但是我有一个问题; 我知道你需要有"MySQL连接器/ NET"和"用于Visual Studio的MySQL"来开发C#应用程序,但安装应用程序的人是否也需要它们？(我可以用程序释放连接器DLL吗？)

谢谢

编辑:最终用户或连接器都需要它们吗？还有什么他们需要的吗？

Answer 1

using MySql.Data;
using MySql.Data.MySqlClient;

namespace Data
{
    public class DBConnection
    {
        private DBConnection()
        {
        }

        private string databaseName = string.Empty;
        public string DatabaseName
        {
            get { return databaseName; }
            set { databaseName = value; }
        }

        public string Password { get; set; }
        private MySqlConnection connection = null;
        public MySqlConnection Connection
        {
            get { return connection; }
        }

        private static DBConnection _instance = null;
        public static DBConnection Instance()
        {
            if (_instance == null)
                _instance = new DBConnection();
           return _instance;
        }

        public bool IsConnect()
        {
            if (Connection == null)
            {
                if (String.IsNullOrEmpty(databaseName))
                    return false;
                string connstring = string.Format("Server=localhost; database={0}; UID=UserName; password=your password", databaseName);
                connection = new MySqlConnection(connstring);
                connection.Open();
            }

            return true;
        }

        public void Close()
        {
            connection.Close();
        }        
    }
}

例:

var dbCon = DBConnection.Instance();
dbCon.DatabaseName = "YourDatabase";
if (dbCon.IsConnect())
{
    //suppose col0 and col1 are defined as VARCHAR in the DB
    string query = "SELECT col0,col1 FROM YourTable";
    var cmd = new MySqlCommand(query, dbCon.Connection);
    var reader = cmd.ExecuteReader();
    while(reader.Read())
    {
        string someStringFromColumnZero = reader.GetString(0);
        string someStringFromColumnOne = reader.GetString(1);
        Console.WriteLine(someStringFromColumnZero + "," + someStringFromColumnOne);
    }
    dbCon.Close();
}

Answer 2

您可以使用程序包管理器将其添加为程序包,这是最简单的方法.你不需要任何其他东西来使用mysql数据库.

或者您可以在Package Manager Console中运行以下命令

PM> Install-Package MySql.Data

NUGET Mysql.Data

Answer 3

您必须从此处下载MySQLConnection NET。

然后，您需要MySql.Data.DLL像这样添加到MSVisualStudio：

1. 打开菜单项目
2. 加
3. 参考
4. 浏览到 C:\Program Files (x86)\MySQL\MySQL Connector Net 8.0.12\Assemblies\v4.5.2
5. 添加MySql.Data.dll

如果您想了解更多信息，请访问：在此处输入链接描述

要在代码中使用，必须导入库：

using MySql.Data.MySqlClient;

通过Click事件连接到Mysql数据库（无SSL模式）的示例：

using System;
using System.Windows;
using MySql.Data.MySqlClient;


namespace Deportes_WPF
{

public partial class Login : Window
{
    private MySqlConnection connection;
    private string server;
    private string database;
    private string user;
    private string password;
    private string port;
    private string connectionString;
    private string sslM;

    public Login()
    {
        InitializeComponent();

        server = "server_name";
        database = "database_name";
        user = "user_id";
        password = "password";
        port = "3306";
        sslM = "none";

        connectionString = String.Format("server={0};port={1};user id={2}; password={3}; database={4}; SslMode={5}", server, port, user, password, database, sslM);

        connection = new MySqlConnection(connectionString);
    }

    private void conexion()
    {
        try
        {
            connection.Open();

            MessageBox.Show("successful connection");

            connection.Close();
        }
        catch (MySqlException ex)
        {
            MessageBox.Show(ex.Message + connectionString);
        }
    }

    private void btn1_Click(object sender, RoutedEventArgs e)
    {
        conexion();
    }
  }

}