[Zope-dev] Re: SQLAlchemy integration experiment

[Martijn Faassen]

Brian Sutherland wrote:
[snip]
> This would probably be close to what I would write for my usecase:
> 
> class Database:
> 
>     implements(IDatabase)
> 
>     def __init__(self, *args, **kw):
>         self._args = args
>         self._kw = kw
> 
>     def scopefunc(self):
>         return None # use default per-thread scoping
> 
>     def session_factory(self):
>         return sessionmaker(*self._args, **self._kw)

I don't think you can use sessionmaker, as that creates a class and you 
need to create an actual session in this place. You'd need 
create_session. You'd also need to implement your scopefunc, otherwise 
you get *no* scoping at all, not even per thread, so return 
thread.get_ident().

Like this:

class Database:
     implements(IDatabase)

     def __init__(self, *args, **kw):
         self._args = args
         self._kw = kw

     def scopefunc(self):
         return thread.get_ident()

     def session_factory(self):
         return create_session(*self._args, **self._kw)

we're ignoring the details of what creates the engine, but if you pass 
'bind' along when you create Database that should take care of it.

Regards,

Martijn