SQLalchemy issue when extending Pyramid application

Question

I have a "Main Application", and in this application I have the following in the init.py file:

def main(global_config, **settings):
    # various config settings
    config.include(site_configs)

def site_configs(config):
    config.add_route('portfolio', '/portfolio', 
    view='mainapp.views.portfolio',   
    view_renderer='/site/portfolio.mako')

And in the views.py I have:

def portfolio(request):
    ## some code here
    project_records = dbsession.query(projects).from_statement(
        'SELECT * FROM projects ORDER by id DESC').all()

return {'project_records': project_records}

And then I have a new application, which I want to extend.

So in the init.py I have done:

from mainapp import site_configs

def main(global_config, **settings):
    # various config settings
    config.include(site_configs)

But when I run this new application, I get the following error (full traceback at the bottom of this message):

UnboundExecutionError: Could not locate a bind configured on mapper 
Mapper|projects|projects, SQL expression or this Session

The sqlalchemy engine has been properly set up in both applications.

Also what I want to do is use the database in the new application and not the one in the original main application.

----------------------------
Full Traceback
----------------------------

URL: http://127.0.0.1:6543/portfolio
Module weberror.evalexception:431 in respond         view
>>  app_iter = self.application(environ, detect_start_response)
Module repoze.tm:23 in __call__         view
>>  result = self.application(environ, save_status_and_headers)
Module pyramid.router:158 in __call__         view
>>  response = view_callable(context, request)
Module pyramid.config:2824 in _rendered_view         view
>>  response = wrapped_view(context, request)
Module pyramid.config:2916 in _requestonly_view         view
>>  response = view(request)
Module mainapp.views:62 in portfolio         view
>>  project_records = dbsession.query(projects).from_statement('SELECT * FROM projects ORDER by id DESC').all()
Module sqlalchemy.orm.query:1579 in all         view
>>  return list(self)
Module sqlalchemy.orm.query:1689 in __iter__         view
>>  return self._execute_and_instances(context)
Module sqlalchemy.orm.query:1694 in _execute_and_instances         view
>>  mapper=self._mapper_zero_or_none())
Module sqlalchemy.orm.session:717 in execute         view
>>  engine = self.get_bind(mapper, clause=clause, **kw)
Module sqlalchemy.orm.session:853 in get_bind         view
>>  ', '.join(context)))

Answer 1

Well this really has nothing to do with Pyramid. You have a global variable dbsession that you are attempting to share between different subapps of your application. If the model is the same for all of your applications then you should just have a single initialization function to configure your global in the main(). If you have different models for different subapps that's fine, but you really shouldn't try to shove them all into the same global in an overlapping fashion, which is what it sounds like is happening here. Maybe you can be more specific about how you're intending for this to work?