On 08/18/2013 07:44 PM, Joshua Harlow wrote:
Using an ORM how does the ORM know what attributes u might access (forgive me if this is a documented sqlalchemy pattern/solution). Doesn't it have to give u back the full model since the ORM layer can't predict what u might do with the model object?
Depends on how you use SQLAlchemy. If you load a model object and then use that model object to get related information, you have little control over the fields in the relation that are loaded; you only really have control over when the relation is loaded into a model.
However, for the most part, code in Nova/Glance/Cinder that uses SQLAlchemy does not use this pattern of finding relations. Instead, code generally uses the SQLAlchemy Query interface to explicitly -- more or less -- ask for the columns in the underlying models that need to be returned or processed.
Best, -jay _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
