Q207562: HOWTO: Delete Tables from a Windows CE Device from VBCE or eVB

Article: Q207562
Product(s): Microsoft Visual Basic for Windows
Version(s): 3.0
Operating System(s): 
Keyword(s): kbToolkit kbVBp500 kbVBp600 kbOSWinCEsearch kbGrpDSVB kbDSupport kbCodeSnippet
Last Modified: 16-NOV-2001

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The information in this article applies to:

- Microsoft Windows CE Toolkit for Visual Basic 6.0 
- Microsoft eMbedded Visual Basic, version 3.0 
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SUMMARY
=======

There is currently no functionality provided on a Windows CE device by which
database tables existing in the database store can be directly deleted. This
article illustrates how this can be accomplished from a Windows CE Toolkit for
Visual Basic (VBCE) or eMbedded Visual Basic application.

MORE INFORMATION
================

The following steps illustrate how to delete non system tables from the database
store. The assumption is made that there are already tables in existence on the
Windows CE device that can be deleted.

Step by Step Example
--------------------

1. Create a new Windows CE project in either Visual Basic or eMbedded Visual
  Basic. Form1 is created by default.

2. Place a list box and a command button on Form1.

3. From the Project menu, choose References and add a reference to either the
  Microsoft CE ADO Control 3.0 or Microsoft CE ADO Control 3.1, whichever is
  the most current version on your computer.

4. Paste the following code into the code window of Form1:

  Option Explicit

  Private Sub Form_Load()
      Dim MyRecordSet
      Dim lMyRecordCount As Long
      Dim lRecordIndex As Long
      Dim sMyTable As String
      
      'initialize controls
      Command1.Caption = "Drop Selected Tables"
      Form1.Caption = "CE Drop Tables"
      Command1.Move 60, 1920, 4695, 495
      List1.Move 60, 60, 4695, 1815
      Form1.Move 0, 0, 4950, 2880
      
      ' Load the ListBox with the Names of Non-System Tables.
      Form1.List1.Clear
      Set MyRecordSet = CreateObject("ADOCE.Recordset")
      MyRecordSet.Open "MSysTables", "", 1, 3
      lMyRecordCount = MyRecordSet.RecordCount
      For lRecordIndex = 0 To lMyRecordCount - 1
          sMyTable = MyRecordSet.Fields("TableName").Value
          If Mid(sMyTable, 1, 4) <> "MSys" Then
              Form1.List1.AddItem sMyTable
          End If
          MyRecordSet.MoveNext
      Next
      MyRecordSet.Close
  End Sub

  Sub Command1_Click()
      Dim iIndex As Integer
      Dim MyRecordSet

      Set MyRecordSet = CreateObject("ADOCE.Recordset")
      For iIndex = Form1.List1.ListCount - 1 To 0 Step -1
          If Form1.List1.Selected(iIndex) Then
              MyRecordSet.Open "DROP TABLE [" & _
                  Form1.List1.List(iIndex) & "]", , 2, 3
              Form1.List1.RemoveItem (iIndex)
          End If
      Next
  End Sub

Note that the CreateObject statements may need to be changed depending on whether
you have ADOCE 3.0 or 3.1 on your computer. 5. Run the project.

Note that you can select and delete the non system tables from the database store
of your Windows CE device.

REFERENCES
==========

Microsoft ActiveX Data Objects for the Windows CE operating system (ADOCE) 3.1
for Windows 3.0 SDK:

  http://msdn.microsoft.com/downloads/default.asp?url=/downloads/sample.asp?url=/msdn-files/027/001/491/msdncompositedoc.xml

For additional information about Microsoft ADO for Windows CE SDK (ADOCE), please
click the article numbers below to view the articles in the Microsoft Knowledge
Base:

  Q196034 HOWTO: Use ADOFILTR.DLL to Transfer Database Tables

  Q221594 HOWTO: Populate a ListView With an ADOCE Recordset in VBCE6

  Q265796 HOWTO: Run ADOCE on the Pocket PC Platform

  Q241402 HOWTO: Run ADOCE on a Palm-Size PC Device

Additional query words: vbce vbce6 evb adoce

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Keywords          : kbToolkit kbVBp500 kbVBp600 kbOSWinCEsearch kbGrpDSVB kbDSupport kbCodeSnippet 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword2 kbVBeMbSearch kbWinCETKVBSearch kbWinCESearch kbVBeMb300
Version           : :3.0
Issue type        : kbhowto

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