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.


Schnell und einfach ohne Anschlusswechsel zur Lycos DSL Flatrate wechseln und 3 Monate kostenlos ab effektiven 5,21 EUR pro Monat im ersten Jahr surfen. http://www.lycos.de/startseite/online/dsl/index.html? prod=DSL&trackingID=email_footertxt



-------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
Sqlalchemy-users mailing list
Sqlalchemy-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users

Reply via email to