HOWTO: Open a Visual FoxPro Table for Read/Write

• Microsoft Visual Basic Enterprise Edition for Windows, version 5.0
• Microsoft Visual Basic Enterprise Edition, 32-bit only, for Windows, version 4.0

SUMMARY

FoxPro 2.x tables can be opened as read/write under DAO. Following the same procedure for Visual FoxPro tables will open the tables as read only. ISAM drivers are being used under DAO. The following method will open free tables and tables that are part of a Visual FoxPro database as read/write with RDO. In addition to providing read/write access to these files, the ODBC driver also provides greater performance than the Installable ISAM driver.

If data validity checks are not made, Visual FoxPro database integrity could be violated for tables that are part of a database.

MORE INFORMATION

1. Create a form with two text boxes and 5 CommandButtons. Be sure to select the Remote Data Object under References for the Project.

2. Place the following captions on command1 through command5 buttons:

   "edit" "update" "quit" ">" "<"

3. Place the following code in the General Declarations section of the form's code:

         Option Explicit
         Dim cn As New rdoConnection
         Dim rs As rdoResultset
         Dim SQL As String
   

         Private Sub Command1_Click()
            rs.edit
         End Sub
   
         Private Sub Command2_Click()
           rs(1) = Text2.Text
           rs.Update
         End Sub
   
         Private Sub Command3_Click()
           rs.Close
           Set rs = Nothing
           cn.Close
           Set cn = Nothing
           Unload Me
         End Sub
   
         Private Sub Command4_Click()
   
            rs.MoveNext
            If Not (rs.EOF) Then
              Text1.Text = rs(0)
              Text2.Text = rs(1)
            Else
              rs.MoveLast
          End If
        End Sub
   
         Private Sub Command5_Click()
           rs.MovePrevious
           If Not (rs.BOF) Then
              Text1.Text = rs(0)
              Text2.Text = rs(1)
           Else
              rs.MoveFirst
           End If
         End Sub
   
         Private Sub Form_Load()
           '
           ' Using a DSN-less connection to open a free table
           '
           cn.Connect = "SourceType=DBF;" _
               & "SourceDB=C:\Vfp\Samples\Data;" _
               & "Driver={Microsoft Visual FoxPro Driver}"
   
           cn.CursorDriver = rdUseOdbc
           cn.EstablishConnection "rdDriverNoPrompt"
   
           SQL = "select * from customer"   'this should be a free table
           Set rs = cn.OpenResultset(SQL, rdOpenKeyset, rdConcurRowVer)
   
           rs.MoveFirst
           Text1.Text = rs(0)
           Text2.Text = rs(1)
         End Sub
   
   

4. Press the F5 key to run the form. Make changes by editing text box 2, pressing edit, and then updating. Verify that changes have been made to the table by running the form several times.

REFERENCES

For more information explaining why Visual FoxPro Databases are opened as read-only under DAO, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q161307
   TITLE     : HOWTO: Use Visual FoxPro Tables in Visual Basic 4.0

   ARTICLE-ID: Q147875
   TITLE     : HOWTO: Use "DSN-Less" ODBC Connections with RDO and DAO