User class extends object, not Base. Actually User class is imported from another package, which is made by my coworker, and I need to separate my work from his. So I have no choice but using classical mapping since the User class is intended to be used with classical mapping.
-- Josh Ha-Nyung Chung <minorbl...@gmail.com> On Wednesday, January 11, 2012 at 1:48 AM, Michael Bayer wrote: > > On Jan 10, 2012, at 11:38 AM, Josh Ha-Nyung Chung wrote: > > I'm running web service using sqlalchemy with apache + wsgi + pyramid > > framework. > > I've initialize metadata like the following: > > > > Base = declarative_base() > > Base.metadata.reflect(bind=my_engine) > > user_table = DP_Base.metadata.tables["user"] > > mapper(User, user_table) > > > > and I'm using scoped session since I'm running apache+wsgi with multiple > > processes and threads. > > weird thing is that, errors occur sometimes saying > > > > ArgumentError: Class '<class 'mypackage.User'>' already has a primary > > mapper defined. Use non_primary=True to create a non primary Mapper. > > clear_mappers() will remove *all* current mappers from all classes. > > Once the error occurs, all the following requests to the web service > > encounter the same errors. Restarting httpd seems to resolve the problem > > temporarily. > > I'm afraid that I'm using reflection and mapping in the wrong way? or Is > > there something that I have to care about among multi-threaded, scoped > > session, and table mapping? > > > > does User extend Base ? In that case, it's already mapped. Unless you have > a real need to use classical mappings there's no need to use mapper() (would > be also curious what lead to that decision as it may be a documentation > issue). > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalchemy@googlegroups.com > (mailto:sqlalchemy@googlegroups.com). > To unsubscribe from this group, send email to > sqlalchemy+unsubscr...@googlegroups.com > (mailto: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. To post to this group, send email to sqlalchemy@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.
