Question

This is just a general question irrespective of database architecture.
I am maintaining an ASP.NET web application. The structure is such that,

Say on ‘Add a new employee’ webform

• The primary key (or the record id to
  be saved with) is initially loaded on form
  load event & displayed as a label
  • So when the form loads, the record id to save with is shown to the user

Positives:

• End user already knows what the id/serial of the form is (even before he saves the form)
• So on form save when he is directed
  to gridview screen (with all entries)
  he can search records easily
  (although the most recent one is at
  the top anyway)

Negatives:

• If he does not save the form, say he
  just cancels after loading the data entry form,
  the id/key initially fetched is
  wasted (in my case it is a sequence
  field fetched on form load from database)

What do you guys do in these scenarios ? Which approach would you recommend for ‘web applications’? And how to facilitate the user with a different approach ? Is our current approach recommended (To me,it wastes the ids/sequence from database)

Answer 1

I’d always recommend not presenting the identity field value for the record being created until the record has been created. The “create a temporary placeholder record first to obtain the identity field value ahead of time” approach can, as you mention, result in wasted IDs, unless you have a process in place to reclaim them.

You can always pop-up a message box when the user presses save that tells them the identity field value of the newly created record.