Hi Gary,
Current M1 already contains a "fake" support for autogenerated columns ...
This is mostly workarounds for SQLServer to allow current Cayenne to work
on top of auto-increment schema without throwing exceptions... With MySQL
this worked even before M1.
I promised to roll out the "real" support for a while, but it turned out
to be a bigger change than originally envisioned. Mainly because of the
issues with managing the object graph during commit when the some keys are
not known before the commit....
Now after two paragraphs of noise, here is the good news ;-)
Auto-generated PKs mostly work in the last nightly build (01/18). You are
more than welcome to try it out. No adapter extentions are needed. Just
open your project in the Modeler, select MySQL adapter, and mark PK
columns (DbAttributes) as "Auto" in the new Modeler.
I say "mostly work" as there are a few things that still have to be
cleaned up:
(1) Modeler schema reverse/forward engineering ignores auto increment. So
you have to check the checkbox manually, and also manually update the
column property in the DB (very easy with phpMyAdmin)
(2) One [rather uncommon] scenario is broken - If a dependent object
obtains it key form another (master) object and master uses autincrement,
you can't replace one master with another for dependent. This is uncommon
as dependent objects are usually tied to their master for their life (e.g.
UserDetail is never reassigned to a different User).
There maybe other special cases that break .... I am doing some
refactoring to make everything more consistent, but M2 may go out even
before this is done, as IMO it is usable in its current state.
Andrus
> I'm evaluating Cayenne for an current project. It's a fairly large,
> existing, database that uses MySQL AUTO_INCREMENT to handle the primary
> key fields. Switching to Cayenne's "pk table" just won't work, there's
> a LOT of legacy data there I just cannot change.
>
> But everything else in Cayenne looks great, and I'd vastly prefer an
> alternative to Hibernate (which I'm using now) and it's constant
> irritations (XML hell, code-generation difficulties, etc.). I swear,
> using that product is like death-by-1000-irritants, particularly for
> bottom-up efforts.
>
> I read back through the Cayenne archives and it looks like support for
> database-generated PK's (such as MySQL's AUTO_INCREMENT) is slated for
> 1.2, which is now at Milestone 1 with Milestone 2 being worked on.
>
> So...
>
> A few of questions:
>
> 1) What is the status for support of db-based PK generation in 1.2? Is
> it there?
>
> 2) Does (or will) 1.2 come with a MySQL adaptor that directly implements
> support for native-pk generation?
>
> 2a) Or is the plan to support the retrieval of db-generated keys in an
> architectural sense, but still leave it as an exercise for the user to
> subclass the MySQL adaptor?
>
> Thanks much. I'll keep dealing with Hibernate, for now, but I'm very
> much hoping Cayenne can save me soon. :-)
>
> - Gary
This archive was generated by hypermail 2.0.0 : Tue Jan 18 2005 - 15:37:50 EST