[Dbix-class] table referencing itself

[John Napiorkowski]

--- Brandon Black <blblack at gmail.com> wrote:

> On 12/20/06, Daniel McBrearty
> <danielmcbrearty at gmail.com> wrote:
> > Is there a way to get the id of the object being
> created in the
> > statement doing the creation? I don't even know if
> the db (postgresql)
> > can do that ... ?
> >
> 
> AFAIK, postgres doesn't support doing this easily
> for an autogenerated
> SERIAL column.
> 
> This type of statement does work however:
> 
> insert into whatever values
> (nextval('public.tree_nodeid_seq'::text),
> currval('public.tree_nodeid_seq'::text), .....);
> 
> Of course, if you really are making a tree or graph,
> and
> self-reference is just a way to say "root-level
> node", I'd say just
> make it nullable and treat nulls as root-level nodes
> and have an
> easier life.

I would have to agree with this sentiment.  I have a
number of self-referencing tables and trying to make
the FK not null is a serious hassle.  I found it
greatly complicated even basic development tasks, like
creating triggers for no particular gain.  So unless
you have a really compelling business need to do it
the way you've outlined I would recommend against it.

--john
> 
> -- Brandon
> 
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