Re: postgres adapater problem with create_table :id => false

JeffV
Tue, 20 Oct 2009 15:43:09 -0000

Solved (at least for now):
I used the composite primary keys plugin but listed only a single (and
fake) primary key:
  set_primary_keys :doc_id  # note plural!

:doc_id is not a PK, and for this logging table it''s possible there is
no combination of columns that will yield a single row, depending on
the timing of multi- inserts. But the insert now works and I can move
on!

Jeff

On Oct 19, 3:14 pm, JeffV
<jeff.h.va...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> I tried the composite_primary_keys (2.3.2) plugin, with the same
> overall result: I cannot insert a row (via Postgres) into a table
> without a PK. My model now has this line:
>    set_primary_keys :doc_id, :user_id, :view_date, :view_time  #
> legacy tbl, include all cols
>
> My insert error is thus:
> Mcolumn "doc_id,user_id,view_date,view_time" does not exist
> P170
> Fparse_expr.c
> L421
> RtransformColumnRef: INSERT INTO "document_ref_access"
("doc_id",
> "user_id",
>  "view_date", "view_time") VALUES (1,
E''W:5:a_name'', ''2009-10-19'',
> ''2009-10-1
> 9 14:52:11.605227'') RETURNING
"doc_id,user_id,view_date,view_time")
>
> The RETURNING clause seems to be causing the problem.  If I set the PK
> to, say, :doc_id (mind you this col is NOT a PK for this table) the
> insert works but the doc_id col is set to NULL. Any other suggestions?
>
> Thanks,
> Jeff
>
> On Oct 16, 12:32 pm, Marnen Laibow-Koser <rails-mailing-l...@andreas-
>
>
>
> s.net> wrote:
> > JeffV wrote:
> > > We have 30-40 tables in a legacy db with no PKs. These tables
hold
> > > various logging events and may be searched by a given day, a
given
> > > user id, a given event, etc., but not by a particular row id. So
there
> > > are reasonable reasons to not have PKs on all tables.
>
> > I think you''re confusing the concept of a *surrogate* PK with
a PK in
> > general.  Sure, in the case of your logging tables, it''s
probably
> > reasonable not to have a separate Rails-style id field (surrogate PK).
> > But it is advisable -- I''d even say essential -- to find some
existing
> > field or combination of fields that can be guaranteed unique for each
> > record, and to declare them as a (perhaps composite) PK.
>
> > > Unfortunately,
> > > AR really like PKs...
>
> > And so it should.  If you don''t want a surrogate PK, then
declare some
> > other field the PK.  The composite_primary_keys plugin may help here.
I
> > maintain -- and I believe big-name DB gurus would say likewise -- that
a
> > table without *some* sort of PK is virtually always a Bad Thing, with
or
> > without Rails. .
>
> > > If I set_primary_key nil I can''t do a create (I get an
interning empty
> > > string error). If I set the PK to an arbitrary integer column
then
> > > that column is set to NULL (on an insert), despite its value
being
> > > passed in the attributes hash... I don''t yet have a
solution.
>
> > See what composite_primary_keys will do for you.
>
> > > Jeff
>
> > > On Sep 16, 6:48 pm, Marnen Laibow-Koser
<rails-mailing-l...@andreas-
>
> > Best,
> > --
> > Marnen Laibow-Koserhttp://www.marnen.org
> > mar...-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
> > --
> > Posted viahttp://www.ruby-forum.com/.