Hey folks, I am looking for a bit of advice. I have a many-to-many
relationship which goes through a middle class:
class Foo(Base):
id = Column(Integer, primary_key=True)
class Bar(Base):
id = Column(Integer, primary_key=True)
class FooToBar(Base):
foo_id = Column(Integer, primary_key=True, ForeignKey("foo.id"))
bar_id = Column(Integer, primary_key=True, ForeignKey("bar.id"))
I want to be able to eagerly-load a tree from a Foo to all its Bars, or a
tree from a Bar to all its Foos, but I do not want to eagerly-load the
entire graph of related Foo and Bar objects. If I naively set up the
relationship, that is what happens:
FooToBar.foo = relationship(Foo, backref="bars", lazy="joined")
FooToBar.bar = relationship(Bar, backref="foos", lazy="joined")
Is there a straightforward way to accomplish tree-like loading? (My actual
code masks the existence of FooToBar with two association_proxy attributes,
but I don't think that is relevant for the example.) Could I generate
two different models (in place of FooToBar), each with a one-way
eager-loading relationship? Or could I use join_depth on the relationship
to cap how far the recursion goes?
Thanks,
Chris
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