Hi
I'd like to use an associationproxy for a simple many-to-one relationship:
class Child(Base):
__tablename__ = 'child'
id = Column(Integer, primary_key=True)
name = Column(Unicode)
class Parent(Base):
__tablename__ = 'parent'
id = Column(Integer, primary_key=True)
child_id = Column(Integer, ForeignKey('child.id')
child_ = relationship(Child)
child = association_proxy('child_', 'name', creator=)
Now 'child' is a read-only, dictionary-like table. I never want to insert
new rows in this table.
So I actually pass the following "creator" to the association_proxy
constructor:
def creator(name):
return Session.query(Child).filter_by(name=name).first()
That does the job for "create". But I cannot find a solution for "update".
On update I'd like to replace the current Child object in the Parent object
by a new Child object read from the 'child' table.
Using a specific setter (in a getset_factory) does not work for me, as the
setter receives the Child object (and the value), not the Parent object –
I'd need a ref to the Parent object to be able to change its Child object
in child_.
Maybe I'm doing it all wrong and using an associationproxy is not the way
to go for that case.
Thanks for any suggestion.
--
Eric Lemoine
Camptocamp France SAS
Savoie Technolac, BP 352
73377 Le Bourget du Lac, Cedex
Tel : 00 33 4 79 44 44 96
Mail : [email protected]
http://www.camptocamp.com
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