I have a potential relationship between Foo and Bar that is defined as follows, and has usually been read-only from legacy data.
All the code works, I just want to make sure I'm handling this case in a clear and concise way. I've (over)simplified the case down to this: class Foo(Base): __tablename__ = 'foo' id = Column(Integer, primary_key=True) name = Column(Unicode(6), nullable=False) bar = relationship("Bar", primaryjoin="Foo.id==Bar.id__foo", uselist=False, back_populates='foo', ) class Bar(Base): __tablename__ = 'bar' id = Column(Integer, primary_key=True) name = Column(Unicode(6), nullable=False) id__foo = Column(Integer, ForeignKey("foo.id"), nullable=True, ) foo = relationship("Foo", primaryjoin="Bar.id__foo==Foo.id", uselist=False, back_populates='bar', ) In a current feature ticket, I'm in a situation where I need to upgrade an instance of Foo with an instance Bar and dealing with some get/create functions that do their own flushes. That block of code basically looks like this: def getcreate_bar(bar_name, foo=None): b = s.query(Bar).filter(Bar.name==bar_name).first() if not b: b = Bar() b.name = bar_name b.id__foo = foo.id if foo else None s.add(b) s.flush(objects=[b, ]) return b foo = s.query(Foo).get(1) if not foo.bar: bar = getcreate_bar(bar_name, foo) foo.bar = bar # attribute needed for additional work s.flush(objects=[foo, ]) # flush only needed if bar isn't new my question covers where I create the `bar` and make it instantly available as a foo attribute. Is there a better way to handle this or make it more readable? If I create a new foo, the flush of `foo` doesn't emit SQL after sqlalchemy decides it doesn't have to. I do need that flush if I already had bar, but it wasn't associated to foo. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.