On Monday 08 February 2010 1:43:23 pm Ed Leafe wrote: > On Feb 8, 2010, at 4:04 PM, Nate Lowrie wrote: > > You think that's better than writing a select statement query with a > > where clause that filters on the column value? I want to try to > > incorporate the uniqueness validation inside the validateRecord because > > I do all the validation there and display all the errors to the user at > > once on the dialog. I would still handle the DBQueryException, I would > > just want a way of bundling the uniqueness check in with the other > > business rules. > > Sure, you could do it that way; if I were doing it, though, I would only > make that extra query if it were very likely that there would be a dupe. > It's like the general approach to protecting against bad parameters: you > could run the test every single time the code gets called, or you can catch > the exception and deal with it then. The former tends to be much slower > than the latter, and should generally be avoided. > > Also, in a multi-user situation, two people could be adding the same > value > at nearly the same time. Both would pass the validateRecord() test, but > only one will actually be able to save, so I'm not really sure what benefit > making that extra call is getting you. > > > -- Ed Leafe >
I think the basic problem is that the uniqueness is determined by the database and that is where you have to go to get the 'truth'. Any test above the backend level is just a best guess at most. -- Adrian Klaver [email protected] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/dabo-users Searchable Archives: http://leafe.com/archives/search/dabo-users This message: http://leafe.com/archives/byMID/[email protected]
