"DAL - Classe DetailProvider" --> Questo mi serve per avere la <List>:
public static List<Joints> GetJoints(string Cod, string CD)
{
Database db;
db = DatabaseFactory.CreateDatabase("Rubrica");
DbCommand dbCommand = db.GetStoredProcCommand("SPJoints");
db.AddInParameter(dbCommand, "@Istituto", DbType.Int16, Cod);
db.AddInParameter(dbCommand, "@CD", DbType.String, CD);
Joints Joint;
List<Joints> JointsList = new List<Joints>();
using (IDataReader dr = db.ExecuteReader(dbCommand))
{
while (dr.Read())
{
Joint = new Joints();
Joint = SetJoints(dr); ;
JointsList.Add(Joint);
}
}
return JointsList;
}
Qui assegno i value:
protected static Joints SetJoints(IDataReader dr)
{
Joints jGiun= new Joints();
if (dr["Chiama"] != DBNull.Value)
{
jGiun.Chiamata = (decimal)dr["Chiama"];
}
if (dr["Descrizione"] != DBNull.Value)
{
jGiun.Descrizione = (string)dr["Descrizione"].ToString().ToUpper();
}
return jGiun;
}
"BL"--> Da qui richiamo il DaL:
using StyleDAL;
public List<Joints> GetJoints(string Cod, string CD)
{
return DetailsProvider.GetJoints(Cod, CD);
}
Spero sia chiaro 
Francesco