django values_list 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 queryset count

# Returns the total number of entries in the database.
Entry.objects.count()

# Returns the number of entries whose headline contains 'Lennon'
Entry.objects.filter(headline__contains='Lennon').count()