I'm working on a school project

I want to get all the information of the bands, which works fine. Until i get to genres. Genre is a bit special, because a band can have multiple genres and vice versa.

So in SQL I have a table Bands, a table Genre and a table Band_Genre If i do the inner join there

SELECT * 
FROM Band 
INNER JOIN Band_Genre 
        ON Band.ID = Band_Genre.BandID

Everything works fine in SQL but when i try a second reader with that statement it returns null.

But what i want to do now is fill the datagrid with the genres themselves, not the ID's. So what i think is that i need to get the ID out of the Inner join and link it to Genre.Name

Maybe this goes a bit far but I would be happy if someone could already get the id's into the ObservableCollection. So that the Datagrid shows Genres: 1, 3 for example.

Thanks in advance

C#
//Property
private ObservableCollection genres;

        public ObservableCollection Genres
        {
            get { return genres; }
            set { genres = value; }
        }
//Method
public static ObservableCollection GetBands()
        {
            ObservableCollection list = new ObservableCollection();
            try
            {
                string provider = ConfigurationManager.ConnectionStrings["ConnectionString"].ProviderName;
                string connectionstring = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

                DbConnection con = DbProviderFactories.GetFactory(provider).CreateConnection();
                con.ConnectionString = connectionstring;
                con.Open();

                DbCommand command = DbProviderFactories.GetFactory(provider).CreateCommand();
                command.CommandType = System.Data.CommandType.Text;
                command.Connection = con;
                command.CommandText = "SELECT * FROM Band";

                //Bands ophalen
                DbDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    Band b = new Band()
                    {                       
                        ID = reader["ID"].ToString(),
                        Name = reader["Name"].ToString(),
                        Picture = reader["Picture"].ToString(),
                        Description = reader["Description"].ToString(),
                        Twitter = reader["Twitter"].ToString(),
                        Facebook = reader["Facebook"].ToString(),
                        //Genres = (Genre)reader["Genres"] lijst van genres kunnen doorgeven, probleem met meerdere genres per band. Kijken filmpje inner joint
                    };

                    if (!DBNull.Value.Equals(reader["Picture"]))
                    {
                        b.Picture = reader["Picture"].ToString();
                    }
                    else
                    {
                        b.Picture = null;
                    }
                    list.Add(b);
                }

                //Genres ophalen via INNER JOIN
                DbCommand command2 = DbProviderFactories.GetFactory(provider).CreateCommand();
                command2.CommandType = System.Data.CommandType.Text;
                command2.Connection = con;
                command2.CommandText = "SELECT * FROM Band INNER JOIN Band_Genre On Band.ID = Band_Genre.BandID";

                 //Bands ophalen
                DbDataReader reader2 = command2.ExecuteReader();
                while (reader2.Read())
                {
                    Genre g = new Genre()
                    {
                       ID = reader2["GenreID"].ToString(),
                       //Name = reader2[


                    };
                }

                reader.Close();
                reader2.Close();
                con.Close();
            }

XAML: