The data contained in the data series can be imported from an OleDbDataReader object. This functionality is exposed to the user via the DataSeries. FillFromDataReader and DataSeriesCollection . FillFromDataReader methods.
Importing a Single OleDbDataReader Column into a Data Series
The user can import the data contained in an OleDbDataReader column using the FillFromDataReader method of the DataSeries class. The method receives two arguments: the reader and the column that must be imported. The data contained in the specified column must be compatible with the data series type. See the General Concepts and Terminology topic for a more detailed description of data series compatibility.
The following example demonstrates a single data series import from an OleDbDataReader object. The example assumes that the DataBinging.mdb file contains a table called Sales. The Sales table is supposed to have a column called SalesAmount, which is of type Number-Double.
VB.NET
' create a bar chart
Dim bar As BarSeries = CType(Chart.Series.Add(SeriesType.Bar), BarSeries)
// create a bar chart BarSeries bar = (BarSeries)Chart.Series.Add(SeriesType.Bar); bar.Appearance.FillMode = AppearanceFillMode.Predefined; bar.Legend.Mode = SeriesLegendMode.DataPoints;
// create a database connection object using the connection string OleDbConnection myConnection = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=DataBinding.mdb");
// create a database command on the connection using query OleDbCommand myCommand = new OleDbCommand("select * from Sales", myConnection);
// open the connection myCommand.Connection.Open();
// create the reader OleDbDataReader myReader; myReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
// import the SalesAmount column into the Values data series bar.Values.FillFromDataReader(myReader, "SalesAmount");
Importing Multiple OleDbDataReader Columns into a Data Series Collection
The user can simultaneously import the data contained in a set of OleDbDataReader columns into the data series contained in a DataSeriesCollection . This is achieved by using the FillFromDataReader method of the DataSeriesCollection class. The method receives two arguments: the reader and the columns that must be imported. The first specified column is imported into the first data series, the second column into the second series, etc.
The following example demonstrates a multiple data series import from an OleDbDataReader object. The example code simultaneously imports the SalesAmount and ProductName columns (of type Text) into the Values and Labels data series of a bar chart.
VB.NET
' create a DataSeriesCollection object
Dim arrSeries As DataSeriesCollection = bar.GetDataSeries(DataSeriesMask.Values Or DataSeriesMask.Labels,DataSeriesMask.None)
' create a string array containing the columns which must be imported
Dim arrColumns() As String = {"SalesAmount", "ProductName"}
