Thanks for the reply. Le vendredi 28 août 2015 18:52:37 UTC+3, Michael Bayer a écrit : > > > > On 8/28/15 3:51 AM, [email protected] <javascript:> wrote: > > Another question is why sqlalchemy produce two queries to get hardwares > collections from a dispositif : > > > >>> some_disp.hardwares > 2015-08-28 10:36:41,722 INFO sqlalchemy.engine.base.Engine SELECT disp_hdw > .iddispositif AS disp_hdw_iddispositif, disp_hdw.idhardware AS > disp_hdw_idhardware, disp_hdw.instance AS disp_hdw_instance > FROM disp_hdw > WHERE %s = disp_hdw.iddispositif > 2015-08-28 10:36:41,725 INFO sqlalchemy.engine.base.Engine (2721L,) > 2015-08-28 10:36:41,768 INFO sqlalchemy.engine.base.Engine SELECT hardware > .hdw_type AS hardware_hdw_type, hardware.id AS hardware_id, hardware.idbox > AS hardware_idbox > FROM hardware > WHERE hardware.id = %s > 2015-08-28 10:36:41,772 INFO sqlalchemy.engine.base.Engine (268L,) > > > There's no context given here, but that would indicate that the > "some_disp" instance has been expired. When you .commit() a session, all > objects are expired by default. This is so that if, when you next operate > on the objects, some other transaction has deleted that row, the session > can let you know that you're working on stale data. See the session docs > for options on how to control this behavior. > Here the context, all in the same session :
>>> from dbaccess import * # import engine, Base and tables objects >>> from sqlalchemy.orm.session import sessionmaker >>> Session = sessionmaker(bind=engine) >>> session = Session() >>> l = session.query(Dispositif).all() >>> some_disp = l[-2] >>> engine.echo = True >>> some_disp.hardwares 2015-08-29 20:34:30,972 INFO sqlalchemy.engine.base.Engine SELECT disp_hdw.iddispositif AS disp_hdw_iddispositif, disp_hdw.idhardware AS disp_hdw_idhardware, disp_hdw.instance AS disp_hdw_instance FROM disp_hdw WHERE %s = disp_hdw.iddispositif 2015-08-29 20:34:30,975 INFO sqlalchemy.engine.base.Engine (2721L,) 2015-08-29 20:34:31,018 INFO sqlalchemy.engine.base.Engine SELECT hardware.hdw_type AS hardware_hdw_type, hardware.id AS hardware_id, hardware.idbox AS hardware_idbox FROM hardware WHERE hardware.id = %s 2015-08-29 20:34:31,022 INFO sqlalchemy.engine.base.Engine (268L,) In fact, *hardwares* can be retrieved in one query. > instead of somewhat like : > > SELECT hardware.hdw_type AS hardware_hdw_type, hardware.id AS hardware_id, > hardware.idbox AS hardware_idbox > FROM hardware > JOIN disp_hdw ON hardware.id = disp_hdw.idhardware > WHERE disp_hdw.iddispositif = %s > > > Le vendredi 28 août 2015 10:20:55 UTC+3, [email protected] a écrit : >> >> Hello, >> >> I want to use assocation proxy pattern >> <http://docs.sqlalchemy.org/en/latest/orm/extensions/associationproxy.html> >> with automap. I tried this code : >> >> >> Base = automap_base() >> >> class Dispositif(Base): >> __tablename__ = 'dispositifs' >> hardwares = association_proxy('disp_hardwares', 'hardware') >> >> class Hardware(Base): >> __tablename__ = 'hardware' >> >> Base.prepare(engine, reflect=True) >> >> but it does not work. >> >> Any help appreciated. >> >> Best regards >> > -- > 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 [email protected] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. > > > -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
