Warning when duplicate records

[Philip Fortuna]

I have a field that permits duplicate records but I need to be warned when I enter a duplicate number. I used old posts to try to solv this problem but I keep getting the message "Procedure declaration does not match description of event or procedure having the same name" (with different codes). The field is named "NSC" and the table "1 - Principal". The code I used was:

Private Sub NSC_BeforeUpdate()
Dim rslt As Integer
   If Nz(DLookup("[NSC]", "1 - Principal", "[NSC]=" & Me.NSC), 0) <> 0 Then
      rslt = MsgBox("Este NID já foi introduzido previamente. Deseja continuar?", vbYesNo)
      If rslt = vbNo Then
        Me.RecNo = Null
         Me.RecNo.SetFocus
      End If
   End If
End Sub

Can anybody tell me what am I doing wrong

[zmbd]

It is because your sub procedure is named incorrectly and doesn't have the correct augments.

Thank you for using the code tags. There are some troubleshooting and setup options that you should look at in the first section: >> Before Posting (VBA or SQL) Code.

As for your specific problem.
Open your form in design mode
Select the control [NSC]
Show the properties box for the control (right click context menu etc...)
Select the events tab
Select the before update event
Click on the [...] button
Select code (NOT macro!)
The vba editor will open
Cut and paste lines 2 thru 9 into the Sub procedure that Access has created for you.
Follow the steps that are outlined in the above link on compile and the like.


Also one should NEVER use non-alphanumerics (except for the underscore "_") for field, or table names. "1 - Principal" is asking for trouble. Even the space is not really a great thing even though it has become common.

>SQL Essentials: SQL Server Data Importing: Do's and Don'ts
Don't use non-alphanumeric characters in staging table/column names
You may not have control over how columns are initially named in the tables containing raw data, but I try to revise legacy column names that may contain spaces or other irregular characters. When column or table names contain non-alphanumeric characters, we're forced to delimit them with square brackets or double quotes. Not only is that kind of code harder to write, it's also harder to read.