Microsoft KB Archive/182131

= ACC97: Datasheet of Chart Not Synchronized with Form or Report =

Article ID: 182131

Article Last Modified on 1/22/2007

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APPLIES TO


 * Microsoft Access 97 Standard Edition

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This article was previously published under Q182131



Advanced: Requires expert coding, interoperability, and multiuser skills.



SYMPTOMS
During the Current event of a form, there is a one-record difference between the values displayed in the chart on the form and the values contained in the datasheet of the chart. The datasheet's values reflect data from the previous record, not the current record. This behavior also occurs during the Format or Print event of the detail section of a report.



CAUSE
The chart itself displays the correct values because Microsoft Access populates it directly from its row source, which is a SQL statement or a saved query. During the Current, Format, and Print events, the data sheet of the chart does not yet contain the data from the row source that appears in the chart itself.



RESOLUTION
If you need to modify a chart characteristic that depends on the data in the current record or on any state produced by an OnCurrent, OnFormat, or OnPrint procedure, you must clear the datasheet of the chart and repopulate it. The following example uses a Visual Basic for Applications procedure to clear and repopulate the datasheet of a chart during the Current event of the form.

 Follow steps 1 - 19 in the "Steps to Reproduce Behavior" section later in this article.  Set the OnCurrent property of the form to the following event procedure:

Private Sub Form_Current Dim chtObj As Object, strRowSource As String Dim rsRowSourceFiltered As Recordset Dim intMaxShippers As Integer Dim i As Integer, j As Integer Set chtObj = Me!chtSync.Object intMaxShippers = 3

' In the chart's RowSource, insert a WHERE ' clause based on the value of the form ' field contained in the chart control's        ' LinkMasterFields property. strRowSource = Left(Me!chtSync.RowSource, _           InStr(Me!chtSync.RowSource, "GROUP BY") - 1) _ & "WHERE " & Me!chtSync.LinkChildFields & _ " = '" & Me(Me!chtSync.LinkMasterFields) & _ "'" & " " & Right(Me!chtSync.RowSource, _           Len(Me!chtSync.RowSource) _            - InStr(Me!chtSync.RowSource, "GROUP BY") + 1) Set rsRowSourceFiltered = CurrentDb. _           OpenRecordset(strRowSource, dbOpenSnapshot)

' Check to see if the filtered recordset has any records. If rsRowSourceFiltered.BOF And _ rsRowSourceFiltered.EOF Then MsgBox "There are no records to chart." Exit Sub End If

' Clear the rows required for the maximum number of        ' data rows. The first row contains the column ' headers. Data rows begin at the second row. With chtObj.Application.DataSheet For i = 1 To intMaxShippers .Rows(i + 1).Include = False Next End With

' Ensure the RecordCount value is updated. rsRowSourceFiltered.MoveLast ' Populate the chart's datasheet with the ' filtered recordset, starting with the ' datasheet's second row. rsRowSourceFiltered.MoveFirst For i = 1 To rsRowSourceFiltered.RecordCount For j = 0 To rsRowSourceFiltered.Fields.Count - 1 ' Assign data to the datasheet cells starting ' at row 2, column 1. chtObj.Application.DataSheet. _                 Cells(i + 1, j + 1).Value = _

rsRowSourceFiltered.Fields(j).Value Next rsRowSourceFiltered.MoveNext Next

With Me!chtSync.Object.Application ' Each datasheet row contains two columns for the ' shipper's CompanyName and SumProductSales. The first ' row contains the column headers. Debug.Print "*** OnCurrent Values ***" For i = 1 To 4 Debug.Print .DataSheet.Cells(i, 1).Value & _ " - " & .DataSheet.Cells(i, 2).Value Next End With

End Sub  Open the form in Form view and press CTRL+G to display the Debug window. Note that the values in the Debug window correspond to those that you see in the chart on the form.



Steps to Reproduce Behavior
CAUTION: Following the steps in this example will modify the sample database Northwind.mdb. You may want to back up the Northwind.mdb file and perform these steps on a copy of the database.

 Open the Product Sales for 1995 query in the sample database Northwind.mdb.</li> Add the Shippers table to the query. Microsoft Access automatically creates a join between the ShipVia field in the Orders table and the ShipperID field in the Shippers table.</li> Drag the CompanyName field from the Shippers table to the first empty column on the query design grid. Leave the Total row for this field set to the default value of Group By.</li> Save and close the query.</li> Create a new form based on the Categories table. Include only the CategoryID and CategoryName fields in the detail section of the form.</li> On the Insert menu, click Chart to create a chart in the detail section of the form.</li> On the first screen of the Chart Wizard, click Queries and select Product Sales for 1995. Click Next.</li> Move the CompanyName field from the Available Fields list to the Fields For Chart list. Then move the ProductSales field from the Available Fields list to the Fields For Chart list. Click Next.</li> Click Next in the chart type screen to select the default type of Column Chart.</li> On the layout screen of the Chart Wizard, click Next.</li> Click OK if you receive the following message:

You must add field CategoryID if you want to use this link.</li> In the Form Fields list, click CategoryName; in the Chart Fields list, click CategoryName, and then click Finish.</li> On the View menu, click Properties and change the Name property of the chart to "chtSync" (without the quotation marks).</li> Save the form as frmChartSync.</li> On the Edit menu, click Select Form. On the View menu, click Properties, and then click the Event tab.</li> Click the OnCurrent property box, and then click the Build (...) button.</li> In the Choose Builder dialog box, click Code Builder. Click OK to display the Form_frmChartSync class module.</li> <li>On the Tools menu, click References.</li> <li>In the References dialog box, scroll down the Available References list and select the Microsoft Graph 8.0 Object Library. Click OK.</li> <li> Set the OnCurrent property of the form to the following event procedure:

Private Sub Form_Current Dim i As Integer With Me!chtSync.Object.Application ' Each datasheet row contains two columns for the ' shipper's CompanyName and SumProductSales. The first ' row contains the column headers. Debug.Print "*** OnCurrent Values ***" For i = 1 To 4 Debug.Print .DataSheet.Cells(i, 1).Value & _ " - " & .DataSheet.Cells(i, 2).Value Next End With End Sub </li> <li>Close the module and insert a command button on the form.</li> <li>View the property sheet of the command button and change the Name property to cmdGraphData and the Caption property to Current Graph Data .</li> <li>Click the OnCurrent property box, and then click the Build (...) button.</li> <li>In the Choose Builder dialog box, click Code Builder. Click OK to display the Form_frmChartSync class module.</li> <li> Set the OnClick property of cmdGraphData to the following event procedure:

Private Sub cmdGraphData_Click Dim i As Integer With Me!chtSync.Object.Application ' Note that this code is the same as            ' that in the Current event procedure. Debug.Print "*** Form View Values ***" For i = 1 To 4 Debug.Print .DataSheet.Cells(i, 1).Value & _ " - " & .DataSheet.Cells(i, 2).Value Next End With End Sub </li> <li>Save the form and switch to Form view.</li> <li>Press CTRL+G to display the Debug window. Note that the Debug window displays the East, West, and North values that correspond to the sample data instead of the actual values that correspond to the current record on the form.</li> <li>Go to the next record. Note that the Debug window now displays Shippers data, but it does not match the data displayed in the chart on the form. The data in the Debug window corresponds to the previous record.</li> <li>Click Current Graph Data. Note that the chart data displayed in the Debug Window now matches that of the current record.</li></ol>

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