Python style filter and order_by with field chain access

0.10.4

✨ Features

• Add Python style to filter and order_by with field access instead of dunder separated strings. #51
  • Accessing a field with attribute access (chain of dot notation) can be used to construct FilterGroups (ormar.and_ and ormar.or_)
  • Field access overloads set of python operators and provide a set of functions to allow same functionality as with dunder separated param names in **kwargs, that means that querying from sample model Track related to model Album now you have more options:
    • exact - exact match to value, sql column = <VALUE>
      • OLD: album__name__exact='Malibu'
      • NEW: can be also written as Track.album.name == 'Malibu
    • iexact - exact match sql column = <VALUE> (case insensitive)
      • OLD: album__name__iexact='malibu'
      • NEW: can be also written as Track.album.name.iexact('malibu')
    • contains - sql column LIKE '%<VALUE>%'
      • OLD: album__name__contains='Mal'
      • NEW: can be also written as Track.album.name % 'Mal')
      • NEW: can be also written as Track.album.name.contains('Mal')
    • icontains - sql column LIKE '%<VALUE>%' (case insensitive)
      • OLD: album__name__icontains='mal'
      • NEW: can be also written as Track.album.name.icontains('mal')
    • in - sql column IN (<VALUE1>, <VALUE2>, ...)
      • OLD: album__name__in=['Malibu', 'Barclay']
      • NEW: can be also written as Track.album.name << ['Malibu', 'Barclay']
      • NEW: can be also written as Track.album.name.in_(['Malibu', 'Barclay'])
    • isnull - sql column IS NULL (and sql column IS NOT NULL)
      • OLD: album__name__isnull=True (isnotnull album__name__isnull=False)
      • NEW: can be also written as Track.album.name >> None
      • NEW: can be also written as Track.album.name.is_null(True)
      • NEW: not null can be also written as Track.album.name.is_null(False)
      • NEW: not null can be also written as ~(Track.album.name >> None)
      • NEW: not null can be also written as ~(Track.album.name.is_null(True))
    • gt - sql column > <VALUE> (greater than)
      • OLD: position__gt=3
      • NEW: can be also written as Track.album.name > 3
    • gte - sql column >= <VALUE> (greater or equal than)
      • OLD: position__gte=3
      • NEW: can be also written as Track.album.name >= 3
    • lt - sql column < <VALUE> (lower than)
      • OLD: position__lt=3
      • NEW: can be also written as Track.album.name < 3
    • lte - sql column <= <VALUE> (lower equal than)
      • OLD: position__lte=3
      • NEW: can be also written as Track.album.name <= 3
    • startswith - sql column LIKE '<VALUE>%' (exact start match)
      • OLD: album__name__startswith='Mal'
      • NEW: can be also written as Track.album.name.startswith('Mal')
    • istartswith - sql column LIKE '<VALUE>%' (case insensitive)
      • OLD: album__name__istartswith='mal'
      • NEW: can be also written as Track.album.name.istartswith('mal')
    • endswith - sql column LIKE '%<VALUE>' (exact end match)
      • OLD: album__name__endswith='ibu'
      • NEW: can be also written as Track.album.name.endswith('ibu')
    • iendswith - sql column LIKE '%<VALUE>' (case insensitive)
      • OLD: album__name__iendswith='IBU'
      • NEW: can be also written as Track.album.name.iendswith('IBU')
• You can provide FilterGroups not only in filter() and exclude() but also in:
  • get()
  • get_or_none()
  • get_or_create()
  • first()
  • all()
  • delete()
• With FilterGroups (ormar.and_ and ormar.or_) you can now use:
  • & - as and_ instead of next level of nesting
  • | - as `or_' instead of next level of nesting
  • ~ - as negation of the filter group
• To combine groups of filters into one set of conditions use & (sql AND) and | (sql OR)

  # Following queries are equivalent:
  # sql: ( product.name = 'Test'  AND  product.rating >= 3.0 ) 
  
  # ormar OPTION 1 - OLD one
  Product.objects.filter(name='Test', rating__gte=3.0).get()
  
  # ormar OPTION 2 - OLD one
  Product.objects.filter(ormar.and_(name='Test', rating__gte=3.0)).get()
  
  # ormar OPTION 3 - NEW one (field access)
  Product.objects.filter((Product.name == 'Test') & (Product.rating >=3.0)).get()

• Same applies to nested complicated filters

  # Following queries are equivalent:
  # sql: ( product.name = 'Test' AND product.rating >= 3.0 ) 
  #       OR (categories.name IN ('Toys', 'Books'))
  
  # ormar OPTION 1 - OLD one
  Product.objects.filter(ormar.or_(
                            ormar.and_(name='Test', rating__gte=3.0), 
                            categories__name__in=['Toys', 'Books'])
                        ).get()
  
  # ormar OPTION 2 - NEW one (instead of nested or use `|`)
  Product.objects.filter(
                        ormar.and_(name='Test', rating__gte=3.0) | 
                        ormar.and_(categories__name__in=['Toys', 'Books'])
                        ).get()
  
  # ormar OPTION 3 - NEW one (field access)
  Product.objects.filter(
                        ((Product.name='Test') & (Product.rating >= 3.0)) | 
                        (Product.categories.name << ['Toys', 'Books'])
                        ).get()

• Now you can also use field access to provide OrderActions to order_by()
  • Order ascending:
    • OLD: Product.objects.order_by("name").all()
    • NEW: Product.objects.order_by(Product.name.asc()).all()
  • Order descending:
    • OLD: Product.objects.order_by("-name").all()
    • NEW: Product.objects.order_by(Product.name.desc()).all()
  • You can of course also combine different models and many order_bys:
    Product.objects.order_by([Product.category.name.asc(), Product.name.desc()]).all()

🐛 Fixes

• Not really a bug but rather inconsistency. Providing a filter with nested model i.e. album__category__name = 'AA'
  is checking if album and category models are included in select_related() and if not it's auto-adding them there.
  The same functionality was not working for FilterGroups (and_ and or_), now it works (also for python style filters which return FilterGroups).