DataTable OttieniDaCAP(string PrimiTreCaratteri)
        {
            DataTable dt= new DataTable();
            SqlCommand c = new SqlCommand();
            c.Connection = new SqlConnection("Stringa di connessione");
            c.Parameters.Add(new SqlParameter("@P1", SqlDbType.NChar));
            c.Parameters["@P1"].Value = @"{PrimiTreCaratteri}%";
            c.CommandType= System.Data.CommandType.Text;
            c.CommandText = "SELECT Comune, Cap, Provincia FROM Congm WHERE Cap Like @P1";
            
            c.Connection.Open();    
            dt.Load(c.ExecuteReader()); 
            c.Connection.Close();
            
            return dt;  
        }