Great, thanks for the follow-up! We've found a workaround using inspect(item).expired_attributes.clear() after calling through to make_transient_to_detached(item).
Best, Neena On Tuesday, September 19, 2017 at 1:38:19 PM UTC-7, Mike Bayer wrote: > > On Tue, Sep 19, 2017 at 1:16 PM, Neena Parikh <ne...@benchling.com > <javascript:>> wrote: > > Hi there, > > > > After implementing the solutions for raising on column usages brought up > at > > https://groups.google.com/forum/#!topic/sqlalchemy/Lbyq8Co95mQ, I've > come > > across an issue where a deferred column is being loaded by default after > a > > series of function calls. Here's the minimal repro I could find: > > great test, added as > > https://bitbucket.org/zzzeek/sqlalchemy/issues/4084/make_transient_to_pending-expires-deferred. > > > > This can be fixed but is targeted at 1.2 (in beta2 right now, beta3 is > nearly ready but moving slowly). Are you able to work around this or > do you need a backport to 1.1 ? > > > > > > > class MyColumn(Column): > > pass > > > > @compiles(MyColumn) > > def compile_column(element, compiler, **kw): > > raise Exception('compile_column') > > > > class MyTable(): > > id = Column(Integer, primary_key=True) > > deferred_column = deferred(MyColumn(...)) > > > > > > > > from sqlalchemy.orm.session import make_transient, > > make_transient_to_detached > > item = MyTable.query.first() # doesn't load deferred_column > > > > make_transient(item) > > make_transient_to_detached(item) > > db.session.add(item) > > db.session.expire_all() > > item.id # Ordinarily, loading item.id should not be accessing > > deferred_column > >> Exception: compile_column > > > > > > > > It looks like it's hitting this line: > > > https://github.com/zzzeek/sqlalchemy/blob/887fb3ebaad20847edc752f5fcf072ace947d56a/lib/sqlalchemy/orm/loading.py#L797, > > > > which seems to be where the column is getting undeferred — is this > behavior > > intentional? (There also may be a simpler way to reproduce this > behavior.) > > If it is intentional, is there anyway to work around this so the column > > isn't loaded in? > > > > (In case it helps, we use make_transient and make_transient_to_detached > for > > tests to ensure each test starts in the same session state even while > using > > nested transactions). > > > > > > Thank you! > > Neena > > > > -- > > 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 <javascript:>. > > To post to this group, send email to sqlal...@googlegroups.com > <javascript:>. > > 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. 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+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.
