I got a question about my connecting the secondSession to the first engine. I was just showing that you can connect the session to whichever engine it needs to connect to.
Change that stuff as needed. If you're second engine should be hooked into the second Session, then do that. As long as each session is bound to a different engine, it should work. - Mike On Jun 9, 10:52 am, Mike Driscoll <[email protected]> wrote: > By popular request, I'm sticking what I did on here: > > I used the pylons docs to figure out part of > this:http://www.pylonshq.com/docs/en/0.9.7/models/#multiple-engines > > Here are the files to change: > > #-------------- > # development.ini > > # create 2 or more sqlalchemy urls > > sqlalchemy.main.url = sqlite:///%(here)s/devdata.db > sqlalchemy.other.url = sqlite:///%(here)s/devdata2.db > > # ------------------------------------------- > > #-------------- > # app_cfg.py (which is in the config folder) > > # need to subclass AppConfig and > # override setup_sqlalchemy > > from sqlalchemy import engine_from_config > from pyretention.model import init_model > > class MyAppConfig(AppConfig): > def setup_sqlalchemy(self): > """Setup SQLAlchemy database engine.""" > engineOne = engine_from_config(pylons_config, > 'sqlalchemy.main.') > engineTwo = engine_from_config(pylons_config, > 'sqlalchemy.other.') > config['pylons.app_globals'].engineOne = engineOne > config['pylons.app_globals'].engineTwo = engineTwo > # Pass the engine to initmodel, to be able to introspect > tables > init_model(engineOne, engineTwo) > > base_config = MyAppConfig() > > # ------------------------------------------- > > #-------------- > # model\__init__.py > > # Global session manager: DBSession() returns the Thread-local > # session object appropriate for the current web request. > maker = sessionmaker(autoflush=True, autocommit=False, > extension=ZopeTransactionExtension()) > DBSession = scoped_session(maker) > > maker2 = sessionmaker(autoflush=True, autocommit=False, > extension=ZopeTransactionExtension()) > secondSession = scoped_session(maker2) > > def init_model(engineOne, engineTwo): > """Call me before using any of the tables or classes in the > model.""" > > DBSession.configure(bind=engineTwo) > > secondSession.configure(bind=engineOne) > > # you only need this metadata > #if you want to autoload a table > second_metadata = MetaData(engineOne) > # ------------------------------------------- > > Note that in websetup, there is a call to > > model.metadata.create_all(bind=config['pylons.app_globals'].sa_engine) > > So when you override AppConfig in app_cfg.py, you'll want to change > one of these lines or hack websetup.py and any other references to > sa_engine: > > config['pylons.app_globals'].engineOne = engineOne > config['pylons.app_globals'].engineTwo = engineTwo > > to > > config['pylons.app_globals'].sa_engine = engineOne > > Hope that helps others. > > - Mike > > On Jun 9, 9:10 am, Mike Driscoll <[email protected]> wrote: > > > For the record, this was resolved. I didn't know how to set up the > > second session object. > > > Thanks! > > > Mike > > > On Jun 5, 2:06 pm, percious <[email protected]> wrote: > > > > It's not too bad, but you have to do your own custom app setup, and > > > modify your init_model stuff to create multiple transaction manager. > > > > app_cfg.py: > > > > from webapp.model import init_model > > > from sqlalchemy import engine_from_config > > > from tg.configuration import AppConfig, Bunch > > > from pylons import config as pylons_config > > > > class MyAppConfig(AppConfig): > > > def setup_sqlalchemy(self): > > > """Setup SQLAlchemy database engine""" > > > users_engine = engine_from_config(pylons_config, > > > 'sqlalchemy_users.') > > > samples_engine = engine_from_config(pylons_config, > > > 'sqlalchemy_samples.') > > > config['pylons.app_globals'].sa_engine = users_engine > > > config['pylons.app_globals'].sa_users_engine = users_engine > > > config['pylons.app_globals'].sa_samples_engine = > > > samples_engine > > > > # Pass the engine to initmodel, to be able to introspect > > > tables > > > init_model(users_engine, samples_engine) > > > > base_config = MyAppConfig() > > > ... > > > > model/__init__.py: > > > > import model.users > > > import model.samples > > > > from model.users.mappers import * > > > from model.samples.mappers import * > > > > from zope.sqlalchemy import ZopeTransactionExtension > > > from sqlalchemy.orm import scoped_session, sessionmaker > > > > # Global session manager. DBSession() returns the session object > > > # appropriate for the current web request. > > > maker = sessionmaker(autoflush=True, autocommit=False, > > > extension=ZopeTransactionExtension()) > > > > DBSession = UsersDBSession = scoped_session(maker) > > > maker3 = sessionmaker(autoflush=True, autocommit=False, > > > extension=ZopeTransactionExtension()) > > > > SamplesDBSession = scoped_session(maker3) > > > from model.users.metadata import metadata as users_metadata > > > from model.samples.metadata import metadata as samples_metadata > > > > def init_model(users_engine, samples_engine): > > > """Call me before using any of the tables or classes in the > > > model.""" > > > > global UsersDBSession, SamplesDBSession, users_metadata, > > > samples_metadata > > > > UsersDBSession.configure(bind=users_engine) > > > SamplesDBSession.configure(bind=samples_engine) > > > > users_metadata.bind = users_engine > > > samples_metadata.bind = samples_engine > > > > This is sort of an off-the cuff answer, we will provide a better one > > > in the next documentation release. > > > > Come find me on IRC if you need some more help. > > > > cheers. > > > -chris > > > > On Jun 4, 10:31 am, Mike Driscoll <[email protected]> wrote: > > > > > Hi, > > > > > According to Mark Ramm's blog, supporting multiple databases is > > > > supposed to be easy > > > > (seehttp://compoundthinking.com/blog/index.php/2008/07/31/10-reasons-why-...). > > > > So where is the documentation that says how to do it?? > > > > > I "think" I need to put multiple sqlalchemy.url's in my > > > > development.ini file. But where oh where do I set up the SA engines > > > > at? The model's __init__ claims to support multiple databases too > > > > using MetaData, but it doesn't show where to bind the engine unless > > > > you're supposed to use the undocumented init_model function somehow. > > > > > I'm pretty sure the init_model came from Perkins. Maybe he can tell me > > > > where to put my call to the function and how to set it up for multiple > > > > databases? > > > > > That would be great! > > > > > Thanks, > > > > > Mike > > > > > On May 28, 12:47 pm, Mike Driscoll <[email protected]> wrote: > > > > > > Hi, > > > > > > I am having a little trouble wrapping my head around how to configure > > > > > my model's __init__.py file for multiple databases. I am working on an > > > > > application that accesses 3 databases and does reflection on select > > > > > tables from all three. > > > > > > I assume I need to comment out this line: > > > > > > metadata = DeclarativeBase.metadata > > > > > > and instead create three metadata instances based on MetaData(), > > > > > correct? > > > > > > Finally, as I understand it, I can use the "init_model" function to do > > > > > the mapping for some of them, but I am not understanding where to > > > > > create the engine object to pass to it. Also, once I have my tables > > > > > mapped in the function, what do I put in my real model file if > > > > > anything? > > > > > > Hopefully that stuff makes sense. I am using Python 2.5 and TG2 in a > > > > > virtualenv on Windows XP. > > > > > > Thanks! > > > > > > Mike > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "TurboGears" group. 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