[Sqlalchemy-tickets] [sqlalchemy] #2847: interpret a Query in Query as aliased(ent, q.subquery()) ?

[sqlalchemy <mi...@zz...>]

#2847: interpret a Query in Query as aliased(ent, q.subquery()) ?
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 Reporter:  zzzeek       |           Owner:  zzzeek
     Type:  enhancement  |          Status:  new
 Priority:  medium       |       Milestone:  0.9.0
Component:  orm          |        Severity:  major - 1-3 hours
 Keywords:               |  Progress State:  in queue
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 Basically, if you were to say
 sess.query(some_query).join(some_other_query) it would act like this:

 {{{
 #!python
 from sqlalchemy import *
 from sqlalchemy.orm import *
 from sqlalchemy.ext.declarative import declarative_base

 Base = declarative_base()

 class A(Base):
     __tablename__ = 'a'

     id = Column(Integer, primary_key=True)
     bs = relationship("B")


 class B(Base):
     __tablename__ = 'b'

     id = Column(Integer, primary_key=True)
     a_id = Column(Integer, ForeignKey('a.id'))

 e = create_engine("sqlite://", echo=True)
 Base.metadata.create_all(e)

 sess = Session(e)

 sess.add_all([A(bs=[B(), B()]), A(bs=[B()])])

 def foo_thing(q):
     ent = q.column_descriptions[0]['expr']
     return aliased(ent, q.subquery())

 q1 = sess.query(A)
 q2 = sess.query(B)

 print sess.query(foo_thing(q1)).join(foo_thing(q2)).all()
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2847>
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