the example is huge can you point out which two queries you'd like to compare?
this: cte = dbsession.query(P2B.id, P2B.parent_id) \ .filter(P2B.id == child_id) \ .cte(name='cte', recursive=True) cte = cte.union( dbsession.query(P2B.id, P2B.parent_id).filter( P2B.id == cte.c.parent_id)) cteids = dbsession.query(cte.c.id) ancestors = dbsession.query(P2B).filter(P2B.id.in_(cteids)).all()[1:] and this? ancestors = dbsession.query( P2B.ancestors).filter(P2B.id == child_id).all() # <<<< child_id IS NEVER USED IN EXPRESSION it might surprise you to know I barely follow what these queries are returning for you, I just look very briefly to get the desired syntax right, so a simple "here's teh code hre's the SQL" is best On Fri, Jun 8, 2018 at 2:44 PM, HP3 <henddher.pedr...@gmail.com> wrote: > Ahhhh!!! Makes perfect sense! > > But there is something still amiss ... > The last 2 assertions are triggering because the query is returning a single > ancestor (self) instead of the whole recursive list. > > See the plain CTE and the @hybrid_property.expression CTE: The where clauses > are still different :( > (and hence the output) > > Are my @hybrid_property.expressions incorrectly declared? > > > CTE ---------------------------------------- > > 2018-06-08 13:14:44,144 INFO sqlalchemy.engine.base.Engine BEGIN (implicit) > > 2018-06-08 13:14:44,145 INFO sqlalchemy.engine.base.Engine WITH RECURSIVE > cte(id, parent_id) AS > > (SELECT p2bases.id AS id, p2bases.parent_id AS parent_id > > FROM p2bases > > WHERE p2bases.id = %(id_1)s UNION SELECT p2bases.id AS p2bases_id, > p2bases.parent_id AS p2bases_parent_id > > FROM p2bases, cte > > WHERE p2bases.id = cte.parent_id) > > SELECT p2bases.id AS p2bases_id, p2bases.uuid AS p2bases_uuid, > p2bases.classname AS p2bases_classname, p2bases.position AS > p2bases_position, p2bases.extras AS p2bases_extras, p2bases.val AS > p2bases_val, p2bases.time AS p2bases_time, p2bases.parent_id AS > p2bases_parent_id > > FROM p2bases > > WHERE p2bases.id IN (SELECT cte.id AS cte_id > > FROM cte) > > 2018-06-08 13:14:44,146 INFO sqlalchemy.engine.base.Engine {'id_1': 20} > > CTE ANCESTORS <__main__.P2Pg object at 0x10bf94be0> > > CTE ANCESTORS <__main__.P2An object at 0x10bf9a160> > > CTE ANCESTORS <__main__.P2KVP object at 0x10bf9a6a0> > > > > @hybrid_property.expression ANCESTORS CLS > ---------------------------------------- > > 2018-06-08 13:14:44,181 INFO sqlalchemy.engine.base.Engine WITH RECURSIVE > cte(id, parent_id) AS > > (SELECT p2bases.id AS id, p2bases.parent_id AS parent_id > > FROM p2bases > > WHERE p2bases.id = p2bases.id UNION SELECT p2bases.id AS id, > p2bases.parent_id AS parent_id > > FROM p2bases, cte > > WHERE p2bases.id = cte.parent_id) > > SELECT cte.id AS cte_id, cte.parent_id AS cte_parent_id > > FROM cte > > WHERE cte.id = %(id_1)s > > 2018-06-08 13:14:44,182 INFO sqlalchemy.engine.base.Engine {'id_1': 20} > > @hybrid_property.expression ANCESTORS CLS (20, 5) > > > > > On Friday, June 8, 2018 at 12:27:28 PM UTC-5, Mike Bayer wrote: >> >> On Fri, Jun 8, 2018 at 12:16 PM, HP3 <henddher...@gmail.com> wrote: >> > Attached the whole file >> >> OK, removing all the "zope" stuff as well as all the other queries >> that aren't noted as failing, I am only looking at this query: >> >> ancestors = dbsession.query(P2B.ancestors).filter(P2B.id == >> child_id).all() # <<<< child_id IS NEVER USED IN EXPRESSION >> >> the problem is that you are re-introducing P2B a second time, rather >> than referring to the columns that your CTE returns, it should be: >> >> ansc = P2B.ancestors >> ancestors = dbsession.query(ansc).filter(ansc.c.id == child_id).all() >> >> this produces SQL that obeys the same form I see at >> https://www.postgresql.org/docs/current/static/queries-with.html. >> >> Since P2B.ancestors produces a new selectable each time, you need to >> assign it to a variable in order to refer to its set of columns >> without re-introducing it. >> >> >> >> >> > >> > >> > On Thursday, June 7, 2018 at 7:01:21 PM UTC-5, HP3 wrote: >> >> >> >> Hello >> >> >> >> >> >> Having difficulty with CTE and @hybrid_property.expression on a >> >> adjacency >> >> list model. >> >> >> >> >> >> class P2B(Base): >> >> __tablename__ = 'p2bases' >> >> id = Column(Integer, primary_key=True) >> >> classname = Column(String) >> >> parent_id = Column( >> >> Integer, >> >> ForeignKey('p2bases.id', ondelete='CASCADE'), >> >> index=True >> >> ) >> >> >> >> parent = relationship( >> >> 'P2B', >> >> primaryjoin='P2B.parent_id == P2B.id', >> >> foreign_keys='P2B.id', >> >> uselist=False >> >> ) >> >> >> >> __mapper_args__ = { >> >> 'polymorphic_identity': 'P2B', >> >> 'polymorphic_on': classname >> >> } >> >> >> >> @hybrid_property >> >> def ancestors(self): >> >> _ancestors = [] >> >> parent = self.parent >> >> while parent is not None: >> >> _ancestors.append(parent) >> >> parent = parent.parent >> >> return _ancestors >> >> >> >> @ancestors.expression >> >> def ancestors(cls): >> >> cte = select([P2B.id, P2B.parent_id]) \ >> >> .where(P2B.id == cls.id) \ # <<<<<< Based on Example1 >> >> .cte(name='cte', recursive=True) >> >> >> >> cte = cte.union( >> >> select([P2B.id, P2B.parent_id]) >> >> .where(P2B.id == cte.c.parent_id) >> >> >> >> ) >> >> return cte >> >> >> >> >> >> >> >> >> >> >> >> >> >> The issue I am facing is that the SQL statement for ancestors >> >> expression >> >> becomes this >> >> >> >> >> >> >> >> >> >> WITH RECURSIVE cte(id, parent_id) AS >> >> >> >> (SELECT p2bases.id AS id, p2bases.parent_id AS parent_id >> >> >> >> FROM p2bases >> >> >> >> WHERE p2bases.id = p2bases.id UNION SELECT p2bases.id AS id, >> >> p2bases.parent_id AS parent_id >> >> >> >> FROM p2bases, cte >> >> >> >> WHERE p2bases.id = cte.parent_id) >> >> >> >> SELECT p2bases.id AS p2bases_id, p2bases.classname AS >> >> p2bases_classname, >> >> p2bases.position AS p2bases_position, p2bases.parent_id AS >> >> p2bases_parent_id, >> >> cte.id AS cte_id, cte.parent_id AS cte_parent_id >> >> >> >> FROM p2bases, cte >> >> >> >> WHERE p2bases.id = %(id_1)s >> >> >> >> {'id_1': 1} >> >> >> >> >> >> >> >> Notice that `P2B.id == cls.id` in the cte becomes `p2bases.id = >> >> p2bases.id`. >> >> >> >> >> >> What am I missing in my @hypbrid_property.expression declaration? >> >> >> >> >> >> How do I use my ancestors @hybrid_property.expression using >> >> session.query(...)? >> >> >> >> ancestors = session.query(P2B.ancestors).get(a_child_id) >> >> >> >> >> >> Example1: >> >> >> >> http://docs.sqlalchemy.org/en/latest/orm/extensions/hybrid.html#correlated-subquery-relationship-hybrid >> > >> > -- >> > 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. >> > To post to this group, send email to sqlal...@googlegroups.com. >> > 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. 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