fixed in master and rel_0_8.
On Jun 15, 2013, at 3:02 PM, Michael Bayer <mike...@zzzcomputing.com> wrote: > I didn't think it would be, but it is a bug, yes, am applying the patch in > http://www.sqlalchemy.org/trac/ticket/2759 right now. > > > On Jun 14, 2013, at 11:52 PM, Seth P <spadow...@gmail.com> wrote: > >> I've encountered what I believe to be a bug in SQLAlchemy (versions 0.8.0 >> and 0.8.1) in a query that joins class/tables that use joined inheritance. >> >> In the code below, I would expect the three queries to produce the same >> output, namely [u'CCC'], but the first one gives a different (incorrect) >> result, [u'BBB']. Is this a bug, or is the query malformed? >> In the second query, adding a seemingly gratuitous join with D fixes the >> problem. And as the third query shows, replacing C by an aliased version >> also fixes the problem. So whatever is going on seems rather subtle. >> >> Thanks, >> >> Seth >> >> >> >> from sqlalchemy import Column, Integer, String, ForeignKey, create_engine >> from sqlalchemy.ext.declarative.api import declarative_base >> from sqlalchemy.orm import relationship, sessionmaker, scoped_session >> from sqlalchemy.orm.util import aliased >> >> Base = declarative_base(object) >> metadata = Base.metadata >> >> class A(Base): >> __tablename__ = 'A' >> idx = Column(Integer, primary_key=True) >> name = Column(String(20), nullable=False) >> type_idx = Column(Integer, nullable=False) >> __mapper_args__ = { 'polymorphic_on':type_idx } >> >> class B(A): >> __tablename__ = 'B' >> idx = Column(Integer, ForeignKey(str(A.__table__) + ".idx"), >> primary_key=True) >> __mapper_args__ = { 'polymorphic_identity':2 } >> >> class C(A): >> __tablename__ = 'C' >> idx = Column(Integer, ForeignKey(str(A.__table__) + ".idx"), >> primary_key=True) >> b_idx = Column(Integer, ForeignKey(str(B.__table__) + ".idx"), >> nullable=False) >> b = relationship("B", foreign_keys=[b_idx]) >> __mapper_args__ = { 'polymorphic_identity':3 } >> >> class D(A): >> __tablename__ = 'D' >> idx = Column(Integer, ForeignKey(str(A.__table__) + ".idx"), >> primary_key=True) >> __mapper_args__ = { 'polymorphic_identity':4 } >> >> class CtoD(Base): >> __tablename__ = 'CtoD' >> idx = Column(Integer, primary_key=True) >> c_idx = Column(Integer, ForeignKey(str(C.__table__) + ".idx"), >> nullable=False) >> c = relationship("C", foreign_keys=[c_idx]) >> d_idx = Column(Integer, ForeignKey(str(D.__table__) + ".idx"), >> nullable=False) >> d = relationship("D", foreign_keys=[d_idx]) >> >> if __name__ == '__main__': >> engine = create_engine('sqlite:///:memory:', echo=False) >> metadata.create_all(bind=engine) >> Session = scoped_session(sessionmaker(bind=engine)) >> session = Session() >> >> # populate tables with a single entry in each table >> b = B(name='BBB') >> c = C(name='CCC', b=b) >> d = D(name='DDD') >> c_to_d = CtoD(c=c, d=d) >> session.add_all([b, c, d, c_to_d]) >> session.commit() >> >> sql_query = session.query(B, C.name).join(C, B.idx == >> C.b_idx).join(CtoD, C.idx == CtoD.c_idx).join(D, CtoD.d_idx == D.idx) >> print [name for (_, name) in sql_query.all()] # [u'BBB'] >> >> sql_query = session.query(B, C.name).join(C, B.idx == >> C.b_idx).join(CtoD, C.idx == CtoD.c_idx) >> print [name for (_, name) in sql_query.all()] # [u'CCC'] >> >> aliased_C = aliased(C) >> sql_query = session.query(B, aliased_C.name).join(aliased_C, B.idx == >> aliased_C.b_idx).join(CtoD, aliased_C.idx == CtoD.c_idx).join(D, CtoD.d_idx >> == D.idx).join(D, CtoD.d_idx == D.idx) >> print [name for (_, name) in sql_query.all()] # [u'CCC'] >> >> >> -- >> 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 http://groups.google.com/group/sqlalchemy. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > > -- > 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 http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/groups/opt_out. > > -- 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 http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.
