vs怎么操作mysql数据库代码

using System;
using MySql.Data.MySqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "Server=localhost;Database=testdb;Uid=root;Pwd=password;";
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            try
            {
                connection.Open();
                string sql = "SELECT * FROM users";
                MySqlCommand command = new MySqlCommand(sql, connection);
                MySqlDataReader reader = command.ExecuteReader();

                while (reader.Read())
                {
                    Console.WriteLine(reader["username"]);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error: " + ex.Message);
            }
        }
    }
}

Install-Package MySql.Data.EntityFramework

using System.Data.Entity;

public class UserContext : DbContext
{
    public DbSet<User> Users { get; set; }

    public UserContext() : base("name=MyConnectionString")
    {
    }
}

public class User
{
    public int Id { get; set; }
    public string Username { get; set; }
}

<connectionStrings>
  <add name="MyConnectionString" connectionString="Server=localhost;Database=testdb;Uid=root;Pwd=password;" providerName="MySql.Data.MySqlClient" />
</connectionStrings>

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        using (UserContext context = new UserContext())
        {
            var users = context.Users.ToList();
            foreach (var user in users)
            {
                Console.WriteLine(user.Username);
            }
        }
    }
}