Re: [Sqlalchemy-tickets] [sqlalchemy] #2725: The sense foreign_keys parameter to orm.relationship is unclear

[sqlalchemy <mi...@zz...>]

#2725: The sense foreign_keys parameter to orm.relationship is unclear
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      Reporter:  amluto            |      Owner:  zzzeek
          Type:  defect            |     Status:  closed
      Priority:  medium            |  Milestone:  0.8.xx
     Component:  documentation     |   Severity:  minor - half an hour
    Resolution:  fixed             |   Keywords:
Progress State:  completed/closed  |
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Changes (by zzzeek):

 * status:  new => closed
 * resolution:   => fixed
 * severity:  no triage selected yet => minor - half an hour
 * status_field:  needs questions answered => completed/closed


Comment:

 Replying to [comment:2 amluto]:
 > Hmm.  That particular example is actually not bad, although I got thrown
 off a bit since I don't use Declarative.  (My project predates
 declarative.)

 Well obviously the declarative use case is the focus of the documentation
 since that's the standard.

 >
 > The actual situation I have is that there are three tables, A, B, and C.
 B is a child of A and C is a child of both A and B.
 >
 > A has a_id, B has a_id (a foreign key to A) and b_id (its primary key).
 C has a_id and b_id.  The catch is that, for each row in C, we require
 that a_id match both a row in A and the a_id from the corresponding row in
 B.  So the ForeignKey to A in the schema is unnecessary, but I still want
 to map it.

 that's a significantly more esoteric use case than the one where a
 Customer has to link to two different Address objects ;).  The `C.a_id`
 column here is essentially redundant.


 > I still think that making the documentation for the foreign_key
 parameter (as opposed to just an example) unambiguous would improve the
 situation.

 I'm guessing that you're referring to the docstring on relationship
 itself, so I have updated this to be more modern and to also refer to the
 previously mentioned sections in rd0aaaf28c640.

-- 
Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2725#comment:3>
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