Isnull filter and complex filters (including or)

0.9.7

Features

• Add isnull operator to filter and exclude methods.

  album__name__isnull=True #(sql: album.name is null)
  album__name__isnull=False #(sql: album.name is not null))

• Add ormar.or_ and ormar.and_ functions that can be used to compose
  complex queries with nested conditions.
  Sample query:

  books = (
      await Book.objects.select_related("author")
      .filter(
          ormar.and_(
              ormar.or_(year__gt=1960, year__lt=1940),
              author__name="J.R.R. Tolkien",
          )
      )
      .all()
  )

  Check the updated docs in Queries -> Filtering and sorting -> Complex filters

Other

• Setting default on ForeignKey or ManyToMany raises and ModelDefinition exception as it is (and was) not supported