absolutely. inheritance is still quite buggy, this will all be fixed
eventually (in 0.2).
On May 18, 2006, at 11:14 AM, Marty McFly wrote:
Hi,
Thanks for the fast answer, Mike! Another small, maybe related
question. Let's say that I override the column names in the mapper
of my base class, for example 'body' instead of 'text', like this:
TextItem.mapper = mapper(TextItem, text_items,
properties = {'body' : text_items.c.text}
)
Post.mapper = mapper(Post, posts,
inherits=TextItem.mapper,
)
When I specify the inheritance as above, the Post.mapper doesn't
use the name override of the base class, so text_items.c.text got
mapped to 'text' instead of 'body' (in the Post class). Wouldn't it
make sense for the inherited mapper to inherit the names (and not
just the sql-columns) as well? Otherwise you have to duplicate all
your renamed properties in your inheriting class, which I would
like to avoid in an OO-context (Post inherits from TextItem, so the
attributes should have the same name).
Well, even though I am a newbie and still have lots of
questions...: just wanted to say that I really like SQLAlchemy and
I think it is a great product. Thanks for all the development and
also the help on the mailing list!
Cheers, Martin
Von: Michael Bayer <[EMAIL PROTECTED]>
An: "Marty McFly" <[EMAIL PROTECTED]>
its because your post mapper is using joined table inheritance, i.e.
joining text_items to posts. so the primary key of "text_items JOIN
posts on text_items.id==posts.id" is a composite of "text_items.id,
posts.id". So.....it considers the primary key of Post id #1 to be
this:
m.get(1,1)
or in 0.2, like:
m.get((1,1))
there is the notion that the primary key of such a join should only
use the single column from "text_items", since the primary key of
"posts" is also the foreign key thats being related to text_items;
its redundant and thats why you intuitively used only one primary key
value in your get() (and also why get_by works).
but it seems like Join object is going to have to analyze the join
condition to see if there is literally a
"table1.primary_key==table2.foreign_and_primary_key" condition since
there are other join conditions with two tables like this where this
rule wouldnt apply. that will require some elaborate logic.....so i
think you have to stick with the "dual id" thing for the near term.
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