XL97: Background Queries Suspended While Macro Executes

ID: Q157090

The information in this article applies to:

• Microsoft Excel 97 for Windows

SYMPTOMS

When you use the Refreshing property as a condition for a loop in a Visual Basic for Applications macro while a query is refreshing in the background, the macro runs indefinitely and may appear to stop responding (hang).

CAUSE

Background queries do not run while macro code is running. When you programmatically update a pivot table or a query table, such that the query is performed in the background, updating is suspended until the macro ends. After the macro ends and control is returned to Microsoft Excel, the background query continues.

WORKAROUND

Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact the Microsoft fee-based consulting line at (800) 936-5200. For more information about the support options available from Microsoft, please see the following page on the World Wide Web:

   http://www.microsoft.com/support/supportnet/refguide/

Method 1

Modify the macro such that the query does not update in the background. To do this, set the BackgroundQuery argument for the Refresh method to False.

NOTE: In the following example, the BackgroundQuery argument for the Refresh method is set to False. When this argument is set to False, control is returned to the next line in the procedure only after the update is completed.

   Dim qTbl As QueryTable

   Sub CreateQueryTable()

      'Create a new query table.
      Set qTbl = ActiveSheet.QueryTables.Add("ODBC;dsn=Northwind", _
      ActiveSheet.Range("A1"), Sql:="Select * from Customers")

      'Refresh the query table.
      qTbl.Refresh BackgroundQuery:=False

     'Display the number of rows returned to the query table.
     MsgBox qTbl.ResultRange.Rows.Count & " Rows Returned"

   End Sub

Method 2

Use the OnTime method to check the Refreshing property of the query table at specific intervals of time. The OnTime method schedules a procedure to run at a specified time. While it waits to execute the scheduled procedure, Microsoft Excel continues to update the query in the background.

NOTE: In the following example, the OnTime method checks the Refreshing property of the background query.

   Dim qTbl As QueryTable

   Sub CreateQueryTable()

      'Create a new query table.
      Set qTbl = ActiveSheet.QueryTables.Add("ODBC;dsn=Northwind", _
         ActiveSheet.Range("A1"), Sql:="Select * from Customers")

      'Refresh the query table in the background.
      qTbl.Refresh BackgroundQuery:=True

      'Run the procedure to loop until the query is refreshed.
      CheckQueryRefreshState

   End Sub

   Sub CheckQueryRefreshState()

      If qTbl.Refreshing Then
         'If the query is still refreshing, call the
         'CheckQueryRefreshState again in one second.
         Application.OnTime Now() + TimeValue("00:00:01"), _
         "CheckQueryRefreshState"
      Else
         'Display the number of rows returned to the query table
         'after the query table is refreshed.
         MsgBox qTbl.ResultRange.Rows.Count & " Rows Returned"
      End If

   End Sub

MORE INFORMATION

In the following macro example, the macro runs indefinitely because the Refreshing property is the condition for a Do While...Loop, and a query is updating in the background.

Dim qTbl As QueryTable

Sub CreateQueryTable()

    'Create a new query table.
    Set qTbl = ActiveSheet.QueryTables.Add("ODBC;dsn=Northwind", _
         ActiveSheet.Range("A1"), Sql:="Select * from Customers")

    'Refresh the query table in the background.
    qTbl.Refresh BackgroundQuery:=True

    'Loop and wait until the query is refreshed.
    Do While qTbl.Refreshing
        DoEvents
    Loop

    'Display the number of rows returned to the query table.
    MsgBox qTbl.ResultRange.Rows.Count & " Rows Returned"

End Sub

Keywords          : kbprg kbtool kbdta kbdtacode xlvbainfo xlquery KbVBA 
Version           : WINDOWS:97
Platform          : WINDOWS

Last Reviewed: May 18, 1999