beregne og tildele id til ny post

[nygammel]

Jeg har en tabell og et skjema som viser en post i tabellen. Jeg ønsker å legge til en kortroll (knapp) i skjemaet som lager ny post og samtidig tildeler id som skal være lik id på siste foregående post +1. Jeg er ny accessbruker men mener jeg har blitt fortrolig med tabeller, spørringer, skjema og kontroller men er ukjent med makroer og VBA (finner ikke ut av dette og trenger hjelp for å kommer over en kneik- automatisk tildeling av verdier i ny post)

[pbaldy]

Translating your post to English is much more likely to get a helpful response.

[Missinglinq]

Shouldn’t do both of these tasks with the button! For the 'new record' button:

DoCmd.GoToRecord , , acNewRec

For the auto-incrementing record number, here's a typical hack. The first code here would be for an IDNumber that is defined in the table as Text datatype. "Number" fields that aren't used for math are frequently defined as Text.

If IDNumber defined as Text:

Private Sub Form_BeforeUpdate(Cancel As Integer)

If Me.NewRecord Then
   If RecordsetClone.RecordCount = 0 Then
   Me.IDNumber = "1"
  Else
    Me.IDNumber = DMax("val([IDNumber])", "YourTableName") + 1
  End If
End If
End Sub

Here's the same code for an IDNumber defined as a Number:

Private Sub Form_BeforeUpdate(Cancel As Integer)
If Me.NewRecord Then
  If RecordsetClone.RecordCount = 0 Then
    Me.IDNumber = 1
  Else
    Me.IDNumber = DMax("[IDNumber]", "YourTableName") + 1
  End If
End If
End Sub

The above has been used safely for multi-user environments, in my experience, because it doesn't assign the ID number until the very last second before the record is saved. This is necessary to decrease the chance of two users getting the same ID number. The only drawback is that the user cannot see the ID number until the record is saved.

In a single user environment, the code can be moved to the Form_Current event and the ID number will appear as soon as a new record is started.

Linq ;0)>

[azhar2006]

Usesomething like

Private Sub Form_Current()
  If Me.NewRecord Then
    On Error Resume Next 'It should never occur, just to be sure...
    Me!MailingListID.DefaultValue = Nz(DMax("[MailingListID]", "tblMailingList"), 0) + 1
  End If
End Sub

[Missinglinq]

That first code sample looks to be a little thin

The second bit of code, assigning the ID in the Form_Current Event, can only be safely done, as I said, if this app is to be used as a stand-alone app. If it were to be used in the Form_Current Event in a multi-user environment, you run the risk of one user starting a New Record, and before he saves that Record, another user starting a New Record, in which case two Records will have the same ID! In multi-user environments the code has to be in the Form_BeforeUpdate event...which fires at the last instant before the Record is saved. Using this strategy I've never had a duplicate ID issued.

Linq ;0)>