What is the difference between the declarative_base() and db.Model?
Looking in the Flask-SQLAlchemy source code the db.Model class is initialized as follows:
self.Model = self.make_declarative_base()And here is the make_declarative_base() method:
def make_declarative_base(self): """Creates the declarative base.""" base = declarative_base(cls=Model, name='Model', metaclass=_BoundDeclarativeMeta) base.query = _QueryProperty(self) return baseThe _BoundDeclarativeMeta metaclass is a subclass of SQLAlchemy's DeclarativeMeta, it simply adds support for computing a default value for __tablename__ (the table name) and also to handle binds.
The base.query property enables Flask-SQLAlchemy based models to access a query object as Model.query instead of SQLAlchemy's session.query(Model).
The _QueryProperty query class is also subclassed from SQLAlchemy's query. The Flask-SQLAlchemy subclass adds three additional query methods that do not exist in SQLAlchemy: get_or_404(), first_or_404() and paginate().
I believe these are the only differences.