[Sqlalchemy-tickets] [sqlalchemy] #2723: SQLAlchemy relationships on inherited attributes fail

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

#2723: SQLAlchemy relationships on inherited attributes fail
-------------------------------------+-------------------------------------
 Reporter:  mitchellrj               |           Owner:  zzzeek
     Type:  defect                   |          Status:  new
 Priority:  medium                   |       Milestone:
Component:  orm                      |        Severity:  no triage selected
 Keywords:  relationship inherited   |  yet
  inheritance foreign key            |  Progress State:  awaiting triage
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 In the given example below, I get the following error while mappers are
 being configured:
 {{{
         if nrte.table_name == b.name:
     AttributeError: 'Join' object has no attribute 'name'
 }}}
 This appears to be because the foreign key is a property of the parent
 model, rather than the target model. Please ignore that this could be
 avoided by using the `id` column as foreign key in the example, as this is
 not possible in my 'real' case.
 {{{
     class Person(Base):
         __tablename__ = 'people'

         id = Column(Integer, primary_key=True)
         type = Column(Enum('staff', 'student'))
         username = Column(String)

         __mapper_args__ = {
             'polymorphic_on': type
         }

     class Staff(A):
         __tablename__ = 'staff'

         id = Column(Integer, ForeignKey(People.id), primary_key=True)

         __mapper_args__ = {
             'polymorphic_identity': 'staff'
         }

     class Department(Base):
         __tablename__ = 'departments'

         id = Column(Integer, primary_key=True)
         head_username = Column(String, ForeignKey(Staff.username))

         head = relationship(Staff)
 }}}

 This is in SQLAlchemy 0.8.0

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2723>
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