Hi Andy,
I think I now understand your point, which I missed earlier. You
don't see a need for a primary key to be defined on a join table.
Apparently, JPOX requires this, and there is nothing in the spec
currently that addresses the issue at all. Unless we change the spec
to disallow the JPOX implementation, it seems that it is de facto a
portability issue.
Hi Craig,
I mentioned this in one of the original JIRA issues on this subject. Either we
define a <primary-key> (to fully-specify the columns to be used, as you say
in your proposed wording) or we have a way of defining that no PK is to be
defined for that join table. I've no problem with allowing both, which is
what Abe is asking for.
I agree JDO should allow both.
JPOX can implement both, but the spec doesn't define how to say that you have
no PK, so consequently how can we ?
We could interpret no <primary-key> element as saying no PK, but I'm of the
opinion that having a PK in a join table is a "best practice" and should be
the default behaviour. Consequently I want a different way to say that there
is no PK. Maybe something like
<join primary-key="false">
I'm not sure whether having a PK in a join table is "best practice" in
general. I think this depends on the data structure. I agree in case of
a map, because the key needs to be unique and the same holds true for
sets. But for others the PK on the join table does not add much value,
does it?
I'm in favor of interpreting a missing <primary-key> element as there is
no primary key on the join table.
Regards Michael
--
Michael Bouschen [EMAIL PROTECTED] Engineering GmbH
mailto:[EMAIL PROTECTED] http://www.tech.spree.de/
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