BUG: VFP CDX with EMPTY Function Is Not Recognized in VB5

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, version 5.0

SYMPTOMS

FoxPro indexes that contain the function EMPTY or ISBLANK will not be recognized in Visual Basic 5.0. Indexes with this function are recognized by Visual Basic 4.0. The following error will be generated under NT:

   An application error has occurred
   and an application error log is being generated.

   VB5.exe
   Exception Access Violation (0xc0000005),Address .........

In Windows 95, no error is returned because the index is not seen.

RESOLUTION

Compare field to " " instead of using EMPTY. The same results are achieved.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a Visual Basic 5.0 project and choose DAO 3.5 under project references.

  state and ono. The CDX file with the same name as the table file will
  contain the indexes.

      Option Explicit

      Dim FoxDataDB As Database
      Dim RS As Recordset
      Dim myidx As Index

      Private Sub Command1_Click()
        RS.Close
        FoxDataDB.Close
        Set RS = Nothing
        Set FoxDataDB = Nothing
        Unload Me
      End Sub
   
      Private Sub Command2_Click()
         For Each myidx In FoxDataDB.TableDefs("customer").Indexes
            Debug.Print myidx.Name
            RS.Index = myidx.Name
         Next
      End Sub
   
      Private Sub Form_Load()
   
      Set FoxDataDB = Workspaces(0).OpenDatabase( _
                         "d:\fpw26\tutorial", _
                         False, False, "FoxPro 2.5;")
         Set RS = FoxDataDB.OpenRecordset("customer", dbOpenTable)
   
      End Sub

      IIF(EMPTY(phone), state, phone)