public void Update(Room roomObj, int id)
 {
     string sqlStr =
     string.Format(
     "Update Room Set R_PetName = '{0}', R_SeatsNumber = '{1}', R_StandsNumber = '{2}', R_Storey = '{3}', R_HasProjector = '{4}', R_Description = '{5}' Where R_ID = '{6}'",
     roomObj.PetName, roomObj.SeatsNumber, roomObj.StandsNumber, roomObj.Storey, roomObj.HasProjector, roomObj.Description,
     id);
     using (SqlCommand cmd = new SqlCommand(sqlStr, this.SqlCn))
     {
         try
         {
             cmd.ExecuteNonQuery();
         }
         catch (Exception ex)
         {
             Exception error = new Exception("Couldn't update the Room! " + ex.Message, ex);
             throw error;
         }
     }
 }
        // room
        public void Insert(Room roomObj, int id)
        {
            string sqlStr = string.Format("Insert Into Room" +
              "(R_PetName, R_SeatsNumber, R_StandsNumber, R_Storey, R_HasProjector, R_Description, R_MP_ID, R_AddedTime) Values" +
              "('{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', '{7}')"
              , roomObj.PetName, roomObj.SeatsNumber,
              roomObj.StandsNumber, roomObj.Storey, roomObj.HasProjector, roomObj.Description, id, DateTime.Now);

            // execute sql statement and insert roomObj data
            using (SqlCommand cmd = new SqlCommand(sqlStr, SqlCn))
            {
                try
                {
                    cmd.ExecuteNonQuery();
                }
                catch (SqlException ex)
                {
                    Exception error = new Exception("Couldn't insert the Room! " + ex.Message, ex);
                    throw error;
                }

            }
        }