' VBA-Funktionen / SQL-Funktionen
Public Function dbSQLFunc(ByVal sFunc As String, ParamArray vExpr() As Variant) _
  As String
Dim parmCount As Integer
parmCount = UBound(vExpr)
 
  Select Case UCase$(sFunc)
    ' IIf(...,...,...) Funktion
    Case "IIF"
      If DbSystem = dbMSAccess Then
        If parmCount = 1 Then
            If Left(vExpr(1), 9) = "dbSQLFunc" Then
                Dim result As String
                result = CallByName(Me, vExpr(1), VbMethod)
                dbSQLFunc = "IIf(" & vExpr(0) & "," & result & ")"
            Else
                dbSQLFunc = "IIf(" & vExpr(0) & "," & vExpr(1) & ")"
            End If
 
            ElseIf parmCount > 1 Then
             dbSQLFunc = "IIf(" & vExpr(0) & "," & vExpr(1) & "," & vExpr(2) & _
               ")"
        End If
      Else
        dbSQLFunc = "CASE WHEN " & vExpr(0) & " THEN " & vExpr(1) & " ELSE " & _
          vExpr(2) & " END"
      End If
  End Select
End Function