C# IDataReader.IsDBNull方法代码示例

 private MeetingRoom(IDataReader reader)
 {
     this.Id = reader.GetInt32(0);
     this.Name = reader.GetString(1);
     this.Capacity = reader.GetInt32(2);
     this.Beacon = reader.IsDBNull(3) ? null : reader.GetString(3);
     this.Timezone = reader.IsDBNull(4) ? null : reader.GetString(4);
 }

        public Person(IDataReader reader)
            : this()
        {
            PersonId = reader.GetInt64(0);

            if (!reader.IsDBNull(1))
                PersonKey = reader.GetString(1);

            if (!reader.IsDBNull(2))
                RedirectPersonId = reader.ReadInt64OrNull(2);

            if (!reader.IsDBNull(3))
                SourceChannelId = reader.GetInt64(3);

            if (!reader.IsDBNull(4))
                Firstname = reader.GetString(4);

            if (!reader.IsDBNull(5))
                Lastname = reader.GetString(5);

            if (!reader.IsDBNull(6))
                DateOfBirth = reader.ReadDateTimeOrNull(6);

            if (!reader.IsDBNull(7))
                Locale = reader.GetString(7);

            if (!reader.IsDBNull(8))
                Gender = reader.GetString(8);

            if (!reader.IsDBNull(9))
                Timezone = reader.GetString(9);

            if (!reader.IsDBNull(10))
                DateCreated = reader.ReadDateTime(10);
        }

        public Conversation(IDataReader reader)
            : this()
        {
            ConversationId = reader.GetInt64(0);

            if (!reader.IsDBNull(1))
                ConversationIdentifier = reader.GetString(1);

            if (!reader.IsDBNull(2))
                Context = reader.GetString(2);
        }

        private static ETejeduria_DetMall mCargarTJD(IDataReader rdr)
        {
            ETejeduria_DetMall oTJ = new ETejeduria_DetMall();
            //oTJ.Id_producto = rdr.IsDBNull(rdr.GetOrdinal("id_producto")) ? String.Empty : rdr.GetString(rdr.GetOrdinal("id_producto"));
            //oTJ.Nu_correficha = rdr.IsDBNull(rdr.GetOrdinal("nu_correficha")) ? String.Empty : rdr.GetString(rdr.GetOrdinal("nu_correficha"));
            oTJ.Nu_secuen = rdr.IsDBNull(rdr.GetOrdinal("nu_secuen")) ? String.Empty : rdr.GetString(rdr.GetOrdinal("nu_secuen"));
            oTJ.Nu_item = rdr.IsDBNull(rdr.GetOrdinal("nu_item")) ? String.Empty : rdr.GetString(rdr.GetOrdinal("nu_item"));
            oTJ.Nu_longmalla = rdr.IsDBNull(rdr.GetOrdinal("nu_longmalla")) ? 0 : rdr.GetDecimal(rdr.GetOrdinal("nu_longmalla"));
            oTJ.St_anulado = rdr.IsDBNull(rdr.GetOrdinal("st_anulado")) ? String.Empty : rdr.GetString(rdr.GetOrdinal("st_anulado"));

            return oTJ;
        }

 /// <summary>
 /// Loads values from a data reader.
 /// </summary>
 /// <param name="reader">The data reader.</param>
 /// <param name="xIndex">The column number of the x-variable.</param>
 /// <param name="yIndex">The column number of the y-variable.</param>
 public void Load(IDataReader reader, int xIndex, int yIndex)
 {
     if (reader == null) throw new ArgumentNullException("reader");
     if (isReadOnly) throw new InvalidOperationException();
     while (reader.Read())
     {
         if (reader.IsDBNull(xIndex) || reader.IsDBNull(yIndex)) continue;
         object xValue = reader.GetValue(xIndex);
         object yValue = reader.GetValue(yIndex);
         Add(Convert.ToDouble(xValue, CultureInfo.InvariantCulture), Convert.ToDouble(yValue, CultureInfo.InvariantCulture));
     }
 }

 public Group(IDataReader reader)
 {
     _id = (int)reader["GroupID"];
     if (!reader.IsDBNull(reader.GetOrdinal("GeoLat")))
         _geoLatitude = float.Parse(reader["GeoLat"].ToString());
     if (!reader.IsDBNull(reader.GetOrdinal("GeoLng")))
         _geoLongitude = float.Parse(reader["GeoLng"].ToString());
     _name = reader["Name"] as string;
     _profile = reader["Profile"] as string;
     _postalCode = reader["PostalCode"] as string;
     _createdDate = (DateTime)reader["CreatedDate"];
 }

 public Menu GetMenu(IDataReader param)
 {
     _menu = null;
     if (param.Read())
     {
         string id = (!param.IsDBNull(param.GetOrdinal("ID"))) ? (param.GetString(param.GetOrdinal("ID"))) : string.Empty;
         string nombre = (!param.IsDBNull(param.GetOrdinal("NOMBRE"))) ? (param.GetString(param.GetOrdinal("NOMBRE"))) : string.Empty;
         string nivel = (!param.IsDBNull(param.GetOrdinal("NIVEL"))) ? (param.GetString(param.GetOrdinal("NIVEL"))) : string.Empty;
         _menu = NewMenu(id, nombre, nivel);
     }
     return _menu;
 }

        public static ColumnInfo GetColumnInfoFrom(IDataReader reader)
        {
            string columnName = reader.IsDBNull(0) ? string.Empty : reader.GetString(0);
            string dataType = reader.IsDBNull(1) ? string.Empty : reader.GetString(1);
            int size = reader.IsDBNull(2) ? 0 : reader.GetInt32(2);
            ColumnInfo column = new ColumnInfo(
                columnName,
                dataType,
                size
                );

            return column;
        }

    public object NullSafeGet(IDataReader rs, string[] names, object owner)
    {
      int typeIndex = rs.GetOrdinal(names[0]);
      int dataIndex = rs.GetOrdinal(names[1]);
      if (rs.IsDBNull(typeIndex) || rs.IsDBNull(dataIndex))
      {
        return null;
      }

      var type = (string) rs.GetValue(typeIndex);
      var data = (string) rs.GetValue(dataIndex);
      return Deserialize(data, type);
    }

    public string GetInspectText(string Location, string objectName, out int viewCount)
    {
        string[] inspectText = new string[inspectTextVariations];
        string returnInspectText = "";
        int inspectTextCount = inspectText.Length;
        viewCount = new int();

        //CLEARS INSPECT TEXT VALUES
        for(int i = 0; i < inspectText.Length; i++) inspectText[i] = "";

        //GETS INSPECT TEXT FROM DATABASE AND PUTS INTO STRING ARRAY
        sqlQuery = "SELECT Id,Name,Inspect_Text,Inspect_Text_Alt,Inspect_Text_Alt_2,Inspect_Text_Type FROM '" + Location + "' WHERE Name Like '" + objectName + "'";
        Debug.Log (sqlQuery);
        dbcmd.CommandText = sqlQuery;
        reader = dbcmd.ExecuteReader();

        while (reader.Read ()) {
            if(!reader.IsDBNull(2)) inspectText[0] = reader.GetString (2);
            if(!reader.IsDBNull(3)) inspectText[1] = reader.GetString (3);
            if(!reader.IsDBNull(4)) inspectText[2] = reader.GetString (4);
        }

        //COUNT FOR EMPTY ARRAYS
        for(int i = 0; i < inspectText.Length; i++) {
            if(inspectText[i] == "") inspectTextCount--;
        }
        /*
        if(!reader.IsDBNull (5))
            inspectType = (InspectType) Enum.Parse(typeof(InspectType), reader.GetString(5));*/

        switch(inspectType) {
        case InspectType.RANDOM:
            int choice = UnityEngine.Random.Range(0, inspectTextCount);
            returnInspectText = inspectText[choice];
            break;
        case InspectType.ORDER:
            if(viewCount < inspectTextCount) returnInspectText = inspectText[viewCount];
            else returnInspectText = inspectText[inspectText.Length - 1];
            break;
        case InspectType.ONCE:
            if(viewCount < inspectTextCount) returnInspectText = inspectText[viewCount];
            else returnInspectText = "";
            break;
        case InspectType.WAIT:
            returnInspectText = inspectText[0];
            break;
        }

        viewCount++;
        return returnInspectText;
    }

 private Employee GetEmployee(IDataReader reader)
 {
     return new Employee(
                     reader.GetString(reader.GetOrdinal("FirstName")),
                     reader.GetString(reader.GetOrdinal("LastName")),
                     reader.GetInt32(reader.GetOrdinal("ReportingScope")),
                     new ReportingArea(
                         reader.GetString(reader.GetOrdinal("SDst")), 
                         reader.GetString(reader.GetOrdinal("PA")), 
                         reader.IsDBNull(reader.GetOrdinal("ZoneName")) ? null : reader.GetString(reader.GetOrdinal("ZoneName")),
                         reader.IsDBNull(reader.GetOrdinal("RegionID")) ? null : (int?)reader.GetInt32(reader.GetOrdinal("RegionID")), 
                         reader.IsDBNull(reader.GetOrdinal("RegionName")) ? null : reader.GetString(reader.GetOrdinal("RegionName")), 
                         (ReportingScope)reader.GetInt32(reader.GetOrdinal("ReportingScope"))));
 }

 private MeetingRoomBooking(IDataReader reader)
 {
     this.Id = reader.GetInt32(0);
     this.Day = reader.GetInt32(1);
     this.From = reader.GetInt32(2);
     this.Till = reader.GetInt32(3);
     this.Users = reader.GetString(4);
     this.meetingRoom = reader.GetInt32(5);
     this.UsersNotified = reader.IsDBNull(6) ? false : reader.GetBoolean(6);
     if (reader.IsDBNull(7))
         this.NotifyUsers = new List<string>();
     else
         this.NotifyUsers = JsonConvert.DeserializeObject<List<string>>(reader.GetString(7));
     this.UsersCheckedIn = reader.IsDBNull(8) ? null : reader.GetString(8);
 }

		public object NullSafeGet(IDataReader rs, string[] names, object owner)
		{
			var ordinal = rs.GetOrdinal(names[0]);
			if (rs.IsDBNull(ordinal))
				return false;
			return rs.GetInt32(ordinal) == 1;
		}

        public object CreateInstance(IDataReader reader)
        {
            if (reader == null)
            {
                throw new ArgumentNullException("reader");
            }

            if (log.IsDebug)
            {
                log.Debug(LogMessages.ObjectInfo_CreatingInstance, forType.Name);
            }

            var fieldTypes = new Type[reader.FieldCount];
            var values = new object[reader.FieldCount];

            for (int i = 0; i < reader.FieldCount; i++)
            {
                fieldTypes[i] = reader.GetFieldType(i);
                values[i] = reader.IsDBNull(i) ? null : reader.GetValue(i);
            }

            var tupleType = GetTupleType(fieldTypes);

            var tuple = Activator.CreateInstance(tupleType, values);

            return tuple;
        }

        protected static bool getBoolean(IDataReader dataReader, int column)
        {
            if (!dataReader.IsDBNull(column))
                return dataReader.GetBoolean(column);

            return false;
        }