On Feb 23, 2010, at 7:28 AM, Kent wrote: > Thanks, and I knew I had brought up similar behavior before, but it > was in the context of merge() by itself (with composite primary > keys). Before I was wondering why merge expires columns that merge() > originally fetched. This seemed like a different issue to me on the > surface, because in this case, I *already* have the persistent > instance in the session *before* calling merge, and merge expired it > anyway. > > Thanks for your help.
that ticket has been committed so if you try out 0.6 trunk it should not be reloading already loaded attributes. > > > On Feb 21, 2:09 pm, Michael Bayer <mike...@zzzcomputing.com> wrote: >> On Feb 21, 2010, at 2:03 PM, Michael Bayer wrote: >> >> >> >> >> >>> On Feb 21, 2010, at 1:51 PM, Michael Bayer wrote: >> >>>> On Feb 20, 2010, at 5:12 PM, Kent wrote: >> >>>>> If I have a persistent instance in my session and I call merge on an >>>>> object that equates to that instance, some attributes (it seems those >>>>> that aren't explicitly set on the merging instance) are expired and >>>>> get re-queried the next time they are referenced. >> >>>>> We will be supporting remote databases and I may be iterating at some >>>>> points over hundreds or more records that I've already queried and are >>>>> persistent, so I wish these wouldn't expire. >> >>>>> Is this behavior intentional? >> >>>> I think we already mentioned this in a previous email. yes, that is the >>>> current behavior and is intentional. If you'd like these to be merged in >>>> as None, set them to None on your incoming instance. Otherwise their >>>> value is undefined and it is the correct behavior for them to be fetched >>>> from the database when requested. >> >>> I think we also mentioned that i was going to investigate limiting this >>> behavior to the load=False condition. that issue still remains as the >>> single test we have which fails upon changing the behavior uses load=False. >> >> yes, its ticket #1681. the issue has already been logged and here is the >> message where I mentioned as much: >> http://groups.google.com/group/sqlalchemy/msg/6057ea3a24a548e9? >> >> >> >>>>> Version 0.5.8 >> >>>>> For example, see the output from this simple script: >> >>>>> ================================= >> >>>>> from sqlalchemy import * >>>>> from sqlalchemy.orm import * >> >>>>> engine = create_engine('postgres://kb:k...@localhost:5444/kb',echo=True) >>>>> metadata = MetaData() >>>>> Session = sessionmaker(bind=engine) >>>>> DBSession = Session() >> >>>>> order_table = Table("orders", metadata, >>>>> Column("orderid", Unicode, primary_key=True), >>>>> Column("type", Unicode) >>>>> ) >> >>>>> class Order(object): >>>>> pass >> >>>>> order_mapper = mapper(Order, order_table) >> >>>>> #metadata.create_all(engine) >> >>>>> o=Order() >>>>> o.orderid=u'SALE25863' >> >>>>> DBSession.query(Order).get(u'SALE25863') >> >>>>> merged=DBSession.merge(o) >> >>>>> merged.orderid >>>>> merged.type #<------------At this point, type is expired >>>>> ################ >> >>>>> ================================================== >> >>>>> output: >>>>> ================================================== >>>>>>>> from sqlalchemy.orm import * >> >>>>>>>> engine = >>>>>>>> create_engine('postgres://kb:k...@localhost:5444/kb',echo=True) >>>>>>>> metadata = MetaData() >>>>>>>> Session = sessionmaker(bind=engine) >>>>>>>> DBSession = Session() >> >>>>>>>> order_table = Table("orders", metadata, >>>>> ... Column("orderid", Unicode, primary_key=True), >>>>> ... Column("type", Unicode) >>>>> ... ) >> >>>>>>>> class Order(object): >>>>> ... pass >>>>> ... >>>>>>>> order_mapper = mapper(Order, order_table) >> >>>>>>>> #metadata.create_all(engine) >>>>> ... >>>>>>>> o=Order() >>>>>>>> o.orderid=u'SALE25863' >> >>>>>>>> DBSession.query(Order).get(u'SALE25863') >>>>> 2010-02-20 05:55:11,859 INFO sqlalchemy.engine.base.Engine.0x...2cd0 >>>>> BEGIN >>>>> 2010-02-20 05:55:11,863 INFO sqlalchemy.engine.base.Engine.0x...2cd0 >>>>> SELECT orders.orderid AS orders_orderid, orders.type AS orders_type >>>>> FROM orders >>>>> WHERE orders.orderid = %(param_1)s >>>>> 2010-02-20 05:55:11,864 INFO sqlalchemy.engine.base.Engine.0x...2cd0 >>>>> {'param_1': 'SALE25863'} >>>>> <__main__.Order object at 0x14ee710> >> >>>>>>>> merged=DBSession.merge(o) >> >>>>>>>> merged.orderid >>>>> u'SALE25863' >> >>>>> ################################# >>>>>>>> merged.type #<------------At this point, type is expired >>>>>>>> ################ >>>>> 2010-02-20 05:55:11,870 INFO sqlalchemy.engine.base.Engine.0x...2cd0 >>>>> SELECT orders.type AS orders_type >>>>> FROM orders >>>>> WHERE orders.orderid = %(param_1)s >>>>> 2010-02-20 05:55:11,870 INFO sqlalchemy.engine.base.Engine.0x...2cd0 >>>>> {'param_1': 'SALE25863'} >>>>> u'SAL' >> >>>>> -- >>>>> You received this message because you are subscribed to the Google Groups >>>>> "sqlalchemy" group. >>>>> To post to this group, send email to sqlalch...@googlegroups.com. >>>>> To unsubscribe from this group, send email to >>>>> sqlalchemy+unsubscr...@googlegroups.com. >>>>> For more options, visit this group >>>>> athttp://groups.google.com/group/sqlalchemy?hl=en. >> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "sqlalchemy" group. >>>> To post to this group, send email to sqlalch...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> sqlalchemy+unsubscr...@googlegroups.com. >>>> For more options, visit this group >>>> athttp://groups.google.com/group/sqlalchemy?hl=en. >> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "sqlalchemy" group. >>> To post to this group, send email to sqlalch...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> sqlalchemy+unsubscr...@googlegroups.com. >>> For more options, visit this group >>> athttp://groups.google.com/group/sqlalchemy?hl=en. >> >> > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalch...@googlegroups.com. > To unsubscribe from this group, send email to > sqlalchemy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sqlalchemy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. 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