PRB: Accessing Visual FoxPro 3.0 Files from Visual Basic 4.0

ID: Q140770

The information in this article applies to:

Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0
Microsoft FoxPro for Windows, version 3.0

SYMPTOMS

When you attempt to open a Microsoft FoxPro for Windows database file by connecting the database file to a Data Control in a Visual Basic version 4.0 program, the DatabaseName dialog box selects only files with the .dbf file name extension. Moreover, if you select a file with the .dbc file name extension, the DatabaseName property of the Data control displays the path without the file name.

CAUSE

This behavior occurs because the Data control in Visual Basic assumes that a .dbc file is an unlinked FoxPro 3.0 table.

The 16-bit edition of Visual Basic version 4.0 cannot read files in the Visual FoxPro version 3.0 format.

RESOLUTION

Use the following steps to work around this problem:

1. Set the Connect property of the Data1 Data control to FoxPro DBC.

2. Add the FoxPro 3.0 database file name to the path in DatabaseName

   property of the Data control. This file must have the .dbc file name
   extension.

3. Select a table in the RecordSource property of the Data control. You can

   now use bound controls on this recordset.

STATUS

Microsoft has confirmed this to be a problem in Visual Basic version 4.0 for Windows. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

FoxPro 3.0 Databases and their associated linked tables are read-only in the 32-bit edition of Visual Basic version 4.0. The 16-bit edition of Visual Basic version 4.0 cannot read files in the Visual FoxPro version 3.0 format with the .dbc or .dbf file name extension. FoxPro creates three types of files that Visual Basic can open through Data Access Methods.

Databases: Has the file name extension .dbc.
Linked Tables: Has the file name extension .dbf.
Unlinked Table: Also has the file name extension .dbf.

When you set the Connect property of the Data control to FoxPro 3.0, clicking the down arrow of the DatabaseName property displays a dialog box that looks for files with the .dbf file name extension. The Data control assumes that FoxPro 3.0 files are unlinked tables, even if the file is a linked table or a database.

If you get the error, "Cannot Access the Bound FoxPro 3.0 bound DBF file," the Data control is attempting to access a linked table as a stand alone table. Follow the steps shown in the Workaround section to eliminate this error message.

Steps to Reproduce Problem

1. Start the 32-bit version of Visual Basic 4.0, or if it is already

   running, click New Project on the File menu.

2. From the toolbox, add a Data control button to the Form1 form.

3. Click the Connect property of the Data Control and then click the down

   arrow to select FoxPro 3.0.

4. Click the DatabaseName property of the Data Control and then click the

   ellipses button to display the DatabaseName dialog box. Note the default
   file name extension is .dbf.

5. Select a .dbc file and click the OK button. Note that Visual Basic has

   truncated the file name out of the database name text box.

Additional query words: update readonly

Keywords          : kbVBp400 
Version           : WINDOWS:4.0
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: November 17, 1998