Simon, you are awesome! That worked perfectly.
Thank you Sir.
On Monday, October 12, 2020 at 11:29:37 AM UTC-7 Simon King wrote:
> On Mon, Oct 12, 2020 at 6:59 PM Imran Akbar <skun...@gmail.com> wrote:
> >
> > Hi,
> >
> > I'm using SQLAlchemy and am generating classes dynamically for my
> database via the Automapping functionality.
> >
> > I need to add a Mixin class with various helper methods to each of these
> automapped classes.
> >
> > I tried to create subclasses of the automapped class with the mixin
> class:
> >
> > db = create_engine(connection_string)
> > automapper = automap_base()
> > automapper.prepare(db, reflect=True)
> > for class_variable in automapper.__subclasses__():
> > new_class = type(class_variable.__name__, (class_variable, Mixins), {})
> >
> > but when I try to use these classes I get errors like:
> >
> > class _ is a subclass of AutomapBase. Mappings are not produced until
> the .prepare() method is called on the class hierarchy.
> >
>
> If you want to add your methods to *every* automapped class, you can
> change the base class used by automap_base(). Something like this:
>
> class MySpecialBaseClass(object):
> # define your helper methods here
> pass
>
> automapper = automap_base(cls=MySpecialBaseClass)
>
> This works because automap_base passes most of its arguments on to
> declarative_base:
>
>
> https://docs.sqlalchemy.org/en/13/orm/extensions/automap.html#sqlalchemy.ext.automap.automap_base
>
> ...and declarative_base accepts a "cls" argument which is used as the
> base class:
>
>
> https://docs.sqlalchemy.org/en/13/orm/extensions/declarative/api.html#sqlalchemy.ext.declarative.declarative_base
>
> Hope that helps,
>
> Simon
>
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