Re: Autoincrement & Sequences

Hello, Paul Meagher wrote: > I think that if you want to do portable db programming you need to resort > to using a sequences table even thought this is inefficient because 1) it > involves an extra query and 2) alot of the processing is done in PHP > userspace (versus c space with the MySQL autoincrement feature). > > The only other option I can think off would be to somehow intercept the > queries before they hit the db and rewrite them to a format that works for > the particular db. > > $sql = "INSERT INTO myTable (text) VALUES ('foo')"; > $db>query($sql, "auto", id); > > For MySQL the SQL would would not need to be rewritten. > > For Postgres the SQL would need to be rewritten (behind the scenes). > > Not sure exactly how Metabase works in this case as I have not had a chance > to look at it too much yet. Using tables with auto-incremented fields was an invention of Metabase. It was a feature that it already had 2 years ago when it when publicly released. Other PHP abstraction layers just borrowed the idea, which I don't have a problem because it is a good idea. Some database have sequences and others have auto-incremented fields. Few databases provide both. Anyway, what matters is that you can emulate sequences portably with auto-incremented fields and not the other way around. This is why sequences is the way to go for truely portable applications. Regards, Manuel Lemos