Oops, missed the Benchling reference in there. Thanks! On Sunday, June 24, 2018 at 7:09:51 PM UTC-7, Mike Bayer wrote: > > other than the imports and missing database setup I had to re-write ( > :) ), great test! issue is logged at > > https://bitbucket.org/zzzeek/sqlalchemy/issues/4286/mapper_subclass_load_via_in-returns > > where I'll try to figure out a decent way to fix. > > On Sun, Jun 24, 2018 at 6:30 PM, <vin...@benchling.com <javascript:>> > wrote: > > Hello! We noticed some weird behavior where our tests were affecting one > > another, and I tracked it down to what I believe is a SQLAlchemy bug. It > > appears that performing a particular query with a joinedload can alter > > future queries that are run without the same joinedload. This appears to > > only happen when using 'polymorphic_load': 'selectin' (and not with > > 'inline'): > > > > from benchling import db > > > > ### Table setup > > class Parent(db.Model): > > __tablename__ = 'parent' > > id = db.Column(db.Integer, primary_key=True) > > > > > > class Child(db.Model): > > __tablename__ = 'child' > > id = db.Column(db.Integer, primary_key=True) > > parent_id = db.Column(db.Integer, db.ForeignKey('parent.id')) > > parent = db.relationship('Parent', backref=db.backref('children')) > > > > type = db.Column(db.String(), nullable=False) > > __mapper_args__ = { > > 'polymorphic_on': type, > > } > > > > class ChildSubclass1(Child): > > __tablename__ = 'child_subclass1' > > id = db.Column(db.Integer, db.ForeignKey('child.id'), > primary_key=True) > > __mapper_args__ = {'polymorphic_identity': 'subclass1', > > 'polymorphic_load': 'selectin'} > > > > > > class Other(db.Model): > > id = db.Column(db.Integer, primary_key=True) > > child_subclass_id = db.Column(db.Integer, > > db.ForeignKey('child_subclass1.id')) > > child_subclass = db.relationship('ChildSubclass1', > > backref=db.backref('others')) > > > > Parent.__table__.create(bind=db.engine) > > Child.__table__.create(bind=db.engine) > > ChildSubclass1.__table__.create(bind=db.engine) > > Other.__table__.create(bind=db.engine) > > > > > > def is_other_in_session(): > > return any(isinstance(model, Other) for model in db.session) > > > > > > ### Bug repro: > > parent = Parent() > > subclass1 = ChildSubclass1(parent=parent) > > other = Other(child_subclass=subclass1) > > db.session.add_all([parent, subclass1, other]) > > db.session.commit() > > > > > > # Test 1: Loading Parent + Children does not load Other > > print '\nTest #1: Loading Parent + Children does not load others' > > db.session.expunge_all() > > assert not is_other_in_session() > > parents = > > > Parent.query.options(db.joinedload(Parent.children.of_type(ChildSubclass1))).all() > > > > assert not is_other_in_session() > > > > print '\nTest #2: Loading Parent + Children + Others loads others as > > expected' > > db.session.expunge_all() > > assert not is_other_in_session() > > parents = > > > Parent.query.options(db.joinedload(Parent.children.of_type(ChildSubclass1)).joinedload(ChildSubclass1.others)).all() > > > > assert is_other_in_session() > > > > print '\nTest #3: Loading Parent + Children should not load others, but > it > > does now' > > db.session.expunge_all() > > assert not is_other_in_session() > > parents = > > > Parent.query.options(db.joinedload(Parent.children.of_type(ChildSubclass1))).all() > > > > assert not is_other_in_session(), 'The above query should not load any > > Others!' > > > > Test #1 and Test #3 are identical, but Test #3 fails because it is run > after > > Test #2 (which does a joinedload on ChildSubclass.others). I thought > this > > might be related to baked queries, but it still fails with > > enable_baked_queries=False . Let me know if there's any other > information I > > can provide that would be useful, or if there are any workarounds we can > use > > right now! > > > > -- > > 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+...@googlegroups.com <javascript:>. > > To post to this group, send email to sqlal...@googlegroups.com > <javascript:>. > > Visit this group at https://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. >
-- 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.
