Thanks for the link. It seems I missed that. On Mon, Aug 29, 2016 at 4:45 PM Mike Bayer <mike...@zzzcomputing.com> wrote:
> > > On 08/29/2016 08:32 AM, mgozda...@starfishstorage.com wrote: > > Hi > > > > I have a question about the difference between .join() and > > .options(joinedload()). > > > > I'm using example from > > > http://docs.sqlalchemy.org/en/rel_1_0/orm/extensions/hybrid.html#working-with-relationships > > (the one with SavingsAccount and User) > > The doc shows SQL for > > > > Session().query(User, > > User.balance).join(User.accounts).filter(User.balance > 5000) > > > > which is > > > > SELECT "user".id AS user_id, "user".name AS user_name, account.balance > > AS account_balance > > FROM "user" JOIN account ON "user".id = account.user_id > > WHERE account.balance > :balance_1 > > > > if I change the Python code to > > > > Session().query(User, > > User.balance).options(joinedload(User.accounts)).filter(User.balance > > > 5000)) > > > > it generates different SQL, which I believe does a cartesian join: > > > > SELECT "user".id AS user_id, "user".name AS user_name, account.balance > > AS account_balance, account_1.id AS account_1_id, account_1.user_id AS > > account_1_user_id, account_1.balance AS account_1_balance > > FROM account, "user" LEFT OUTER JOIN account AS account_1 ON "user".id = > > account_1.user_id > > WHERE account.balance > :balance_1 > > > > Is there something I'm missing? > > joinedload() only refers to collections that are fully loaded on User > and aren't part of what you can manipulate in the query. Take a look at > > http://docs.sqlalchemy.org/en/latest/orm/loading_relationships.html#the-zen-of-eager-loading > . > > > > > > > > > -- > > 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 > > <mailto:sqlalchemy+unsubscr...@googlegroups.com>. > > To post to this group, send email to sqlalchemy@googlegroups.com > > <mailto:sqlalchemy@googlegroups.com>. > > Visit this group at https://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to a topic in the > Google Groups "sqlalchemy" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/sqlalchemy/ACO-Jhdud3w/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://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 sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
