8.2. ORM QuerySet — Python
Lazy evaluated
Combine queries
Object creation
Write ForeignKey on object
save()
>>> Model.save() >>> Model.objects.all() >>> Model.objects.get() >>> Model.objects.filter() >>> Model.objects.exclude() >>> Model.objects.distinct() >>> Model.objects.get().query >>> Model.objects.all()[:5] >>> Model.objects.all()[5:10] >>> Model.objects.order_by('publish_date')[0]
8.2.1. Filtered QuerySets are unique
>>> q1 = Entry.objects.filter(headline__startswith="What") >>> q2 = q1.exclude(pub_date__gte=datetime.date.today()) >>> q3 = q1.filter(pub_date__gte=datetime.date.today())
8.2.2. QuerySets are lazy
>>> q = Entry.objects.filter(headline__startswith="What") >>> q = q.filter(pub_date__lte=datetime.date.today()) >>> q = q.exclude(body_text__icontains="food") >>> print(q)