values_list django code example

Example 1: what is values_list in django orm

Test.objects.all()                                  time: 0.010061947107315063
 Test.objects.all().values('first')                  time: 0.00578328013420105
 Test.objects.all().values_list('first')             time: 0.005257354974746704
 Test.objects.all().values_list('first', flat=True)  time: 0.0052023959159851075
 Test.objects.all().only('first')                    time: 0.011166254281997681

Example 2: query set

A QuerySet is a list of a dictionary of objects in your database.

Example 3: django order by

class Meta:
        ordering = ('date',)

Example 4: get queryset

from myapp.models import Purchase
from myapp.serializers import PurchaseSerializer
from rest_framework import generics

class PurchaseList(generics.ListAPIView):
    serializer_class = PurchaseSerializer

    def get_queryset(self):
        """
        This view should return a list of all the purchases
        for the currently authenticated user.
        """
        user = self.request.user
        return Purchase.objects.filter(purchaser=user)

Example 5: django 3.0 queryset examples

>>> Entry.objects.filter(
...     headline__startswith='What'
... ).exclude(
...     pub_date__gte=datetime.date.today()
... ).filter(
...     pub_date__gte=datetime.date(2005, 1, 30)
... )