HOWTO: Use ADOFILTR.DLL to Transfer Database Tables

This article demonstrates how to use the ADOCE API (the ADOFILTR.DLL exports) in Visual Basic to programmatically import and export data tables between the desktop and a remote device.

ADOFILTR.DLL, Pocket Access file converter and synchronizer, is a part of the ActiveX Data Objects 2.0 SDK for Windows CE (ADOCE 2.0). It allows programmatic transfer of database tables between the host desktop computer and the remote device. It runs on the desktop computer, not the remote device. The desktop initiates and controls the transfer process. For additional information on ADOCE 2.0, please see the following article in the Microsoft Knowledge Base: The sample code provided below transfers a table in the Biblio.mdb sample database between the desktop and the remote device. Before trying this sample, you need to make sure that ADOCE 2.0 is already installed on the remote device.

Modify Biblio.MDB

Referential integrity rules may interfere with table import. Therefore, the Biblio database must be modified to have a table without relationships. You can use the Visual Data Manager add-in in Visual Basic to modify Biblio.MDB and create a new table.

1. In the Visual Data Manager, open Biblio.MDB.
2. In the SQL window, insert and execute the following SQL statement:

   SELECT Authors.* INTO Authors2 FROM Authors WHERE (Authors.AU_id < 50)
   						

   This will create a new table called "Authors2" with the data from the original Authors table.

Create the Project to Import and Export Tables

1. In Visual Basic, create a new standard EXE project. Form1 is generated by default.
2. Add a CommandButton (Command1) to Form1. Set the caption property to "Device to PC."
3. Add a second CommandButton (Command2) to Form1. Set the caption property to "PC to Device."
4. Add the following code to the declarations section of the form module:

         Private Declare Function DESKTOPTODEVICE _
            Lib "c:\program files\windows ce services\adofiltr.dll" _
            (ByVal desktoplocn As String, _
            ByVal tablelist As String, _
            ByVal sync As Boolean, _
            ByVal overwrite As Integer, _
            ByVal devicelocn As String) As Long
   
         Private Declare Function DEVICETODESKTOP _
           Lib "c:\program files\windows ce services\adofiltr.dll" _
           (ByVal desktoplocn As String, _
           ByVal tablelist As String, _
           ByVal sync As Boolean, _
           ByVal overwrite As Integer, _
           ByVal devicelocn As String) As Long
   					

5. Add the following code to the Click event procedure of Command1:

         Dim result As Long, sPath As String, sTableList As String
         spath = "c:\Program Files\DevStudio\VB\biblio.mdb"
         sTableList = "Authors2.."
   
         ' Change mouse pointer to hourglass.
         Screen.MousePointer = vbHourglass
   
         ' import table from remote device.
         result = DEVICETODESKTOP( sPath, sTableList, False, False, "")
   
         ' Return mouse pointer to normal.
         Screen.MousePointer = vbDefault
   
         If result = 0 Then
            MsgBox "Transfer Successful"
         Else
            MsgBox "An error occurred transferring the data: " & result
         End If
   					

6. Add the following code to the Click event procedure of Command2:

         Dim result As Long, sPath As String, sTableList As String
         spath = "c:\Program Files\DevStudio\VB\biblio.mdb"
         sTableList = "Authors2.."
   
         ' Change mouse pointer to hourglass.
         Screen.MousePointer = vbHourglass
   
         'Export table to remote device.
         result = DESKTOPTODEVICE(sPath, sTableList, False, False, "")
   
         ' Return mouse pointer to normal.
         Screen.MousePointer = vbDefault
   
         If result = 0 Then
            MsgBox "Transfer Successful"
         Else
            MsgBox "An error occurred transferring the data: " & result
         End If
   						

   NOTE: The paths given in the declaration and procedures are for default Installations; modify them according to your system.

Errors that may occur (not an exhaustive list):

NOTE: The values above are the result of subtracting the vbObjectError constant from the raw error value.

Microsoft Windows CE ActiveX Data Objects SDK 2.0 Help