There are a couple of approaches you may use.
- The easier but somewaht not so elegant is to add a duplicate preventing valid_if expression in the [Attendance ID] column of the attendance table.
The expression in valid_if of [Attendance ID] in child “Attendance” table can be something like
(AND([_THIS] = [Attendance ID], [Name with Initial]=[_THISROW].[Name with Initial]))
Here “Attendance” is name of the Attendance table. Please change suitably.
This will prevent more than one child record being created for the same day per person. However, it will NOT hide the “New” button after adding one record in the attendance table.
Please take a look at the last part of the article below on duplicates prevention approach.
- There are more elegant ways but a bit cumbersome to implement. I will post references to those soon.
Edit: Please refer posts below
Edit: Some edit to expression to make it person specific.