VERIFY DUPLICATE DATA BEFORE SAVE

[Guest]

I looking to check the data in a fiel just after dataentry and before
continue to enter the next data field. In a Form. Im using access 2003 and
2007.

 

[Allen Browne]

Use the BeforeUpdate (if you want to cancel it) or AfterUpdate (if you just
to to notify the user) of the control. Use DLookup() to check for a
duplicate in the table.

This kind of thing:

Dim strWhere As String
Dim varResult As Variant
With Me.City
If IsNull(.Value) Or (.Value = .OldValue) Then
'do nothing
Else
strWhere = "[City] = """ & .Value & """"
varResult = DLookup("ID", "Table1", strWhere)
If Not IsNull(varResult) Then
MsgBox "Duplicate"
'Cancel = True
End If
End If
End With

For help with DLookup(), see:
Getting a value from a table: DLookup()
at:
http://allenbrowne.com/casu-07.html