From: Lennon Day-Reynolds <rcoder@...>
Date: 2004-07-29T08:58:36+09:00
Subject: Re: Stupid ODBC!

Warren: thanks for the pointer. That function does indeed tell you
which columns serve as a unique identifier for the table, but it
doesn't directly support the functionality I need for the Active
Record adapter: namely, immediately after inserting a row, fetch the
unique, internal, and hopefully immutable id for that row.

Nathaniel: While SQL Server does have convenience functions for
checking the current/most recent identity value, it does not require
that you have any IDENTITY column in a table schema at all. In fact,
many database design guidelines suggest you avoid them entirely, as
they are simple numeric identifiers which have no semantic
relationship to the data in your column. I'm not enough of a SQL
Server guru to know in practice what portion of tables will lack an
IDENTITY field, but I do know that the possibility, along with the
suggestions I've seen in "best practices" documents to avoid them,
makes me nervous about relying on that feature.

All: I've email David about the issue, and hopefully we'll be able to
figure out a minimally-invasive way to seperate the unique id
functionality in the database adapters from the insert method.

I'm happy to have more suggestions in the meantime, though.

Lennon