Django order by most frequent value

Question

I have a model that represent foodtrucks.

class FoodTruck(models.Model):
    name = models.CharField(max_length=30)
    location = models.TextField()
    creation_date = models.DateTimeField(default=datetime.now)
    start_date = models.DateTimeField(null=True, blank=True)

    def __unicode__(self):
      return self.name

There will be many rows in this table with the same name (but different locations). In my view I want to order the list by name (that has the highest occurrence).

Example Table:

name | location | creation_date | start_date
clover | ABC | ...
chens | XYZ | ...
clover | ABC | ...

My goal is to list the food trucks and how many times they’ve appeared over the last 30 days across all locations, sorted with the most frequent ones first.

Answer 1

This is a job for aggregation.

from django.db.models import Count
FoodTruck.objects.values_list('name').annotate(truck_count=Count('name')).order_by('-truck_count')