Inoltre in rete ho trovato questo:

'**************************************
' Name: AllowZeroLength
' Description:All fields in the selected
' table are processed and the AllowZeroLen
' gth property of the fields are set to ei
' ther True or False, depending on the Sta
' tus given as the finaal parameter The fu
' nction returns a boolean value that can
' be used by the user to determin other op
' erations.
' By: Killcrazy
'
' Inputs:strDatabase = Full database pat
' h
strTableName = Name of table To be processed
Status : True / False
'
' Returns:True/False
'
'This code is copyrighted and has' limited warranties.Please see http://w
' ww.Planet-Source-Code.com/xq/ASP/txtCode
' Id.2279/lngWId.1/qx/vb/scripts/ShowCode.
' htm'for details.'**************************************



Function AllowZeroLength(strDatabase As String, strtablename As String, status As Boolean) As Boolean
Dim db As Database
Dim td As TableDef
Dim fd As Field
On Error Goto Error_Handler
Set db = OpenDatabase(strDatabase)
Set td = db.TableDefs(strtablename)
'loop through the fields in the selected
' recordset


For Each fd In td.Fields
'Check the field type, and only change t
' he value of text and memo fields


If fd.Type = dbText Or dbMemo Then


If status = True Then
fd.AllowZeroLength = True
Else
fd.AllowZeroLength = False
End If
End If
Next fd
AllowZeroLength = True
' Exit Early to avoid error handler.
Exit Function
Error_Handler:
' Raise an error.
Err.Raise Err.Number, "AllowZeroLength", "Could Not process fields.", Err.Description
AllowZeroLength = False
' Reset normal error checking.
Resume Next
End Function


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