Many columns with same value

[Erica]

Hi, I have a dynamic column chart in code-behind. I take the values from a table in my database and the values are divided by month (each month is a row in my table and each column is a group). However, my chart is showing 12 different columns with the same value for the same group. For example: in January, I have the value 10 and in February value 20 for Group A. In the chart, it is showing 12 columns with the value 10 in January and 12 columns with the value 20 in February. (I'm sorry I couldn't post a picture). I need only one column in each month. Can anyone help me with that?

 ​

At first, I'm just getting a value from one of my table columns as a test.

Here is my code:

 

    Dim chartGroups As New RadHtmlChart()
    chartGroups.ID = "chartGroups"
    chartGroups.Width = Unit.Pixel(1200)
    chartGroups.Height = Unit.Pixel(600)

    chartGroups.Legend.Appearance.Position = Telerik.Web.UI.HtmlChart.ChartLegendPosition.Bottom

    chartGroups.PlotArea.XAxis.Items.Add("Jan")
    chartGroups.PlotArea.XAxis.Items.Add("Feb")
    chartGroups.PlotArea.XAxis.Items.Add("Mar")
    chartGroups.PlotArea.XAxis.Items.Add("Apr")
    chartGroups.PlotArea.XAxis.Items.Add("May")
    chartGroups.PlotArea.XAxis.Items.Add("Jun")
    chartGroups.PlotArea.XAxis.Items.Add("Jul")
    chartGroups.PlotArea.XAxis.Items.Add("Aug")
    chartGroups.PlotArea.XAxis.Items.Add("Sep")
    chartGroups.PlotArea.XAxis.Items.Add("Oct")
    chartGroups.PlotArea.XAxis.Items.Add("Nov")
    chartGroups.PlotArea.XAxis.Items.Add("Dec")

    chartGroups.PlotArea.XAxis.TitleAppearance.Text = "Month"
    chartGroups.PlotArea.YAxis.TitleAppearance.Text = "Total"

    Dim chartDataTable As DataSet
    chartDataTable = Program_TypeGrouping_Controller.GetOrderIntake_ByYear(ddlYear.SelectedValue, 0)

Dim npColumnSeries As New ColumnSeries
    Dim groupIntake As New SeriesItem
    Using reader As DataTableReader = chartDataTable.CreateDataReader()

        While reader.Read()

            Dim test As Double

            If reader.IsDBNull(3) Then
                test = 0
            Else
                test = reader(3)
            End If


            npColumnSeries.Stacked = False
            groupIntake.Name = reader.GetName(3)
            npColumnSeries.Spacing = 0
            groupIntake.YValue = test
            npColumnSeries.LabelsAppearance.Visible = False

            npColumnSeries.SeriesItems.Add(groupIntake.YValue)
            chartGroups.PlotArea.Series.Add(npColumnSeries)

        End While
    End Using

    HtmlChartHolder.Controls.Add(chartGroups)

 

[Slav]

Hello Erica,

If I understand your scenario correctly, you need to create one ColumnSeries with a CategorySeriesItem for each category of the HtmlChart. Your current implementation inserts a ColumnSeries instance for each record in the data source, which result in having multiple columns in each category, instead of only one.

You can change this by inserting the ColumnSeries instance only once, as shown in the sample page I attached to this post. I would also suggest checking the following help article for a better understanding of how column series are configured: http://docs.telerik.com/devtools/aspnet-ajax/controls/htmlchart/chart-types/column-chart

Regards,
Slav
Telerik