Microsoft KB Archive/172592

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Knowledge Base


Article ID: 172592

Article Last Modified on 7/2/2004



APPLIES TO

  • Microsoft Visual Basic 5.0 Enterprise Edition
  • Microsoft Visual Basic 6.0 Enterprise Edition
  • Microsoft Visual Basic 4.0 32-Bit Enterprise Edition



This article was previously published under Q172592

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.

NOTE: The Source in the connect statement above will need to be altered for your system. Source points to a directory containing the table.

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:

161307 : How To Use Visual FoxPro Tables in Visual Basic 4.0



For more information on using DSN-Less connections, please see the following article in the Microsoft Knowledge Base:

147875 : How To Use "DSN-Less" ODBC Connections with RDO and DAO



Additional query words: kbVBp500 kbVBp600 kbdse kbDSupport kbVBp kbVBp400 kbDAO kbVFP200

Keywords: kbhowto KB172592