Re: [Sqlalchemy-tickets] [sqlalchemy] #2900: relationship aliased on subclass causes infinite recursion

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

#2900: relationship aliased on subclass causes infinite recursion
---------------------------+-------------------------------
      Reporter:  scraper   |      Owner:  zzzeek
          Type:  defect    |     Status:  new
      Priority:  highest   |  Milestone:  0.9.xx
     Component:  orm       |   Severity:  major - 1-3 hours
    Resolution:            |   Keywords:
Progress State:  in queue  |
---------------------------+-------------------------------

Comment (by zzzeek):

 OK figuring out what's happening here, and also considering what exactly
 is `synonym()` for really, if we can just do this?  What is basically the
 pattern here is that the `InstrumentedAttribute` is just assigned a second
 time somewhere else. declarative isn't really getting involved here other
 than just setting the attribute.  same pattern in classical:

 {{{
 #!python
 from sqlalchemy import Column, Integer, ForeignKey, Table, MetaData
 from sqlalchemy.orm import relationship, backref, mapper

 m = MetaData()
 child = Table('child', m,
         Column('id', Integer, primary_key=True),
         Column('foo_id', ForeignKey('foo.id'))
     )

 foo = Table('foo', m,
         Column('id', Integer, primary_key=True)
     )
 class Child(object):
     pass

 class Foo(object):
     pass

 class FooChild(Child):
     pass

 mapper(Child, child, properties={
         'foo': relationship(Foo, backref=backref('children'))
     })

 mapper(Foo, foo)
 mapper(FooChild, None, inherits=Child)

 Child.parent = Child.foo
 Child.brap = Child.foo_id

 fc = FooChild()
 fc.parent = Foo()
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2900#comment:2>
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