Hvordan opretter man forbindelse til MySQL-databasen?

Installer Oracles MySql.Data NuGet-pakke.

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

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

        public string Server { get; set; }
        public string DatabaseName { get; set; }
        public string UserName { get; set; }
        public string Password { get; set; }

        private MySqlConnection Connection { get; set;}

        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={0}; database={1}; UID={2}; password={3}", Server, DatabaseName, UserName, Password);
                Connection = new MySqlConnection(connstring);
                Connection.Open();
            }
    
            return true;
        }
    
        public void Close()
        {
            Connection.Close();
        }        
    }
}

Eksempel:

var dbCon = DBConnection.Instance();
dbCon.Server = "YourServer";
dbCon.DatabaseName = "YourDatabase";
dbCon.UserName = "YourUsername";
dbCon.Password = "YourPassword";
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();
}