Solved Function as Boolean (1 Viewer)

[ClaraBarton]

I think I don't understand Boolean functions. You helped me here last night so here I am again. My function does what it's supposed to do but it doesn't return anything. It creates a query -- qryOut filled with a recordset. Then I want to export it. I need the boolean part to error out when there are too many records or no fields or anything else that might go wrong. I thought if it was successful it would return yes but it never does. It always returns fail when I know it didn't fail when going back to the calling sub. What is wrong here?

Public Function GetSql() As Boolean
On Error GoTo errHandler

Dim i As Integer
Dim sFields As String
Dim sFilter As String
Dim rsTmp As DAO.Recordset
Dim db As Database
Dim sSource As String
Dim lngNumRecords As Long


 For i = 0 To lstExportFields.ListCount - 1
        If Trim$(sFields) <> "" Then
            sFields = sFields & ","
        End If
        sFields = sFields & "[" & lstExportFields.ItemData(i) & "]"
 Next
        If sFields = "" Then
            MsgBox "Please select some fields to export first"
            Exit Function
        End If
    
    If IsTableOrQuery(txtSource) Then
        txtSource = "[" & txtSource & "]"
    Else
        txtSource = "(" & Replace$(txtSource, ";", "") & ")"
    End If
          sSource = "SELECT " & sFields & " FROM " & Me!txtSource
    If Nz(txtFilter) = "" Then
        i = MsgBox("Are you sure you want to export all records?", _
            vbQuestion + vbOKCancel, "Export All Records?")
        If i = vbCancel Then
            Exit Function
        End If
    Else
        sFilter = " WHERE " & RemoveFormRef(txtFilter)
        sSource = sSource & sFilter
    End If
 
    Set db = CurrentDb
    Set rsTmp = db.OpenRecordset( _
            Name:=sSource, _
            Type:=dbOpenSnapshot, _
            Options:=dbReadOnly)
  
             lngNumRecords = rsTmp.RecordCount
    rsTmp.Close
Set rsTmp = Nothing

    If lngNumRecords = 0 Then
        MsgBox "no Matching Records found", vbOKOnly, "No Records Found"
        DoCmd.Close acForm, "frmExport"
    Else
        If IsNull(DLookup("name", "msysobjects", "name='qryOut'")) Then
            CurrentDb.CreateQueryDef "qryOut", sSource
        Else
            Dim qd As QueryDef
            Set qd = CurrentDb.QueryDefs("qryOut")
            qd.SQL = sSource
            Set qd = Nothing
        End If
    End If
Set db = Nothing
Exit_Function:
    Exit Function
    
errHandler:
    MsgBox "ERROR # " & Err.Number & vbCrLf & _
        Err.Description, vbCritical + vbOKOnly, _
        "Error in Export Function"
        Resume Exit_Function
            
End Function


Private Sub cmdExport_Click()
On Error GoTo Err_cmdExport

Dim strPath As String
Dim qryOut As QueryDef
If GetSql() Then
        
        strPath = CurrentProject.Path & _
            "\" & Me.FileName & Me.Extension
            
                DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel12Xml, _
                    qryOut, strPath, True
                    
        MsgBox "Done!"
        DoCmd.Close acForm, "frmExport"
Else
    MsgBox "Something here isn't right. " _
        & "Either exit or try again.", vbOKOnly, "Failed Export"

End If
Exit_cmdExport:
    Exit Sub
    
Err_cmdExport:
    MsgBox "ERROR # " & Err.Number & vbCrLf & _
        Err.Description, vbCritical + vbOKOnly, _
        "Error in Export Function"
        Resume Exit_cmdExport
            
End Sub

 

[theDBguy]

Hi. For a function to return something, you'll have to assign it a value. Here's what I would usually have.

Public Function TrueOrFalse() As Boolean
On Error GoTo errHandler

Dim boolResult As Boolean

boolResult = True

'do some stuff here

errExit:
    TrueOrFalse = boolResult
    Exit Function

errHandler:
    boolResult = False
    'error handler here
    Resume errExit

End Function

Hope that helps...

 

[arnelgp]

Public Function GetSql() As Boolean
On Error GoTo errHandler

Dim i As Integer
Dim sFields As String
Dim sFilter As String
Dim rsTmp As DAO.Recordset
Dim db As Database
Dim sSource As String
Dim lngNumRecords As Long

GetSql = False

For i = 0 To lstExportFields.ListCount - 1
        If Trim$(sFields) <> "" Then
            sFields = sFields & ","
        End If
        sFields = sFields & "[" & lstExportFields.ItemData(i) & "]"
Next
If sFields = "" Then
        MsgBox "Please select some fields to export first"
        Exit Function
End If
    
If IsTableOrQuery(txtSource) Then
        txtSource = "[" & txtSource & "]"
Else
        txtSource = "(" & Replace$(txtSource, ";", "") & ")"
End If
sSource = "SELECT " & sFields & " FROM " & Me!txtSource
If Nz(txtFilter) = "" Then
        i = MsgBox("Are you sure you want to export all records?", _
            vbQuestion + vbOKCancel, "Export All Records?")
        If i = vbCancel Then
            Exit Function
        End If
    Else
        sFilter = " WHERE " & RemoveFormRef(txtFilter)
        sSource = sSource & sFilter
    End If
 
    Set db = CurrentDb
    Set rsTmp = db.OpenRecordset( _
            Name:=sSource, _
            Type:=dbOpenSnapshot, _
            Options:=dbReadOnly)
 
             lngNumRecords = rsTmp.RecordCount
    rsTmp.Close
Set rsTmp = Nothing

    If lngNumRecords = 0 Then
        MsgBox "no Matching Records found", vbOKOnly, "No Records Found"
        DoCmd.Close acForm, "frmExport"
    Else
        GetSql = True
        If IsNull(DLookup("name", "msysobjects", "name='qryOut'")) Then
            CurrentDb.CreateQueryDef "qryOut", sSource
        Else
            Dim qd As QueryDef
            Set qd = CurrentDb.QueryDefs("qryOut")
            qd.SQL = sSource
            Set qd = Nothing
        End If
    End If
Set db = Nothing
Exit_Function:
    Exit Function
    
errHandler:
    MsgBox "ERROR # " & Err.Number & vbCrLf & _
        Err.Description, vbCritical + vbOKOnly, _
        "Error in Export Function"
        GetSql = False
        Resume Exit_Function
            
End Function

 

[ClaraBarton]

Feeling stupid here... I put BoolResult = False and GetSql = BoolResult at the beginning of the function and then at the end when everything is finished with no fails and we're going back to the calling sub I put BoolResult = True. So shouldn't the calling form get that true result?

 

[ClaraBarton]

Oh, I'm sorry... I didn't see arnelpg's reply. I'm trying that.

 

[ClaraBarton]

Thank you so much, arnelpg. It works beautifully.

 

[arnelgp]

Initially set it to False, since it is in early stage of the code and we might "exit the function early".
see the last If..Else...End If, I am setting it to True (when everything is ok at this point).
but if error occurs, i again reset it to False (see errHandler code).

 

[theDBguy]

Feeling stupid here... I put BoolResult = False and GetSql = BoolResult at the beginning of the function and then at the end when everything is finished with no fails and we're going back to the calling sub I put BoolResult = True. So shouldn't the calling form get that true result?

Yes, sounds like it should, but I guess it doesn't matter now. Glad to hear you got it sorted out.

Good luck with your project.