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Chart for .NET / User's Guide / Data Manipulation / Importing / Importing from OleDbDataReader

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    Importing from OleDbDataReader
    In This Topic

    The data contained in the data series can be imported from an OleDbDataReader. This functionality is exposed to the user via the FillFromDataReader methods of the NDataSeries and NDataSeriesCollection classes.

     Importing a single OleDbDataReader column into a data series

    The user can import the data contained in an OleDbDataReader column with the help of the FillFromDataReader method of the NDataSeries class. The method receives two arguments - the reader and the column, which must be imported. The data contained in the specified column must be compatible with the data series type (see the   topic for a more detailed description of data series compatibility).

    The following example demonstrates a single data series import from an OleDbDataReader. 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.

    C#
    Copy Code
    // 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);
    
    // create a bar chart
    NBarSeries bar = (NBarSeries)chart.Series.Add(SeriesType.Bar);
    
    // import the SalesAmount column into the Values data series
    bar.Values.FillFromDataReader(myReader, "SalesAmount");
    
    Visual Basic
    Copy Code
    ' 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
    Dim myCommand As OleDbCommand =  New OleDbCommand("select * from Sales",myConnection)
    
    ' open the connection
    myCommand.Connection.Open()
    
    ' create the reader
    Dim myReader As OleDbDataReader
    myReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection)
    
    ' create a bar chart
    Dim bar As NBarSeries = chart.Series.Add(SeriesType.Bar)
    
    ' import the SalesAmount column into the Values data series
    bar.Values.FillFromDataReader(myReader, "SalesAmount")
    
     Importing multiple OleDbDataReader columns into a data series collection

    You can simultaneously import the data contained in a set of OleDbDataReader columns into several data series contained in a NDataSeriesCollection . This is achieved with the help of the FillFromDataReader method of the NDataSeriesCollection class. The method receives two arguments - the reader and the columns, which 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. The example code simultaneously imports the SalesAmount and ProductName (of type Text) columns into the Values and Labels data series of a bar chart.

    C#
    Copy Code
    // create a NDataSeriesCollection object
    NDataSeriesCollection arrSeries = bar.GetDataSeries(DataSeriesMask.Values |
    DataSeriesMask.Labels, DataSeriesMask.None);
    
    // create a string array containing the columns which must be imported
    string[] arrCollumns = { "SalesAmount", "ProductName" };
    
    // import the columns into the data series
    arrSeries.FillFromDataReader(myReader, arrCollumns);
    
    Visual Baisc
    Copy Code
    ' create a NDataSeriesCollection object
    Dim arrSeries As NDataSeriesCollection =  bar.GetDataSeries(DataSeriesMask.Values Or DataSeriesMask.Labels,DataSeriesMask.None)
    
    ' create a string array containing the columns which must be imported
    Dim arrCollumns() As String = {"SalesAmount", "ProductName"}
    
    ' import the columns into the data series
    arrSeries.FillFromDataReader(myReader, arrCollumns)
    
     Related Examples
    Windows forms: All Examples\Data Manipulation\Importing\From OleDbDataReader
    See Also