django order_by query set, ascending and descending

Reserved.objects.filter(client=client_id).order_by('-check_in')

A hyphen "-" in front of "check_in" indicates descending order. Ascending order is implied.

We don't have to add an all() before filter(). That would still work, but you only need to add all() when you want all objects from the root QuerySet.

More on this here: https://docs.djangoproject.com/en/dev/topics/db/queries/#retrieving-specific-objects-with-filters

You can also use the following instruction:

Reserved.objects.filter(client=client_id).order_by('check_in').reverse()

Adding the - will order it in descending order. You can also set this by adding a default ordering to the meta of your model. This will mean that when you do a query you just do MyModel.objects.all() and it will come out in the correct order.

class MyModel(models.Model):

    check_in = models.DateField()

    class Meta:
        ordering = ('-check_in',)

Reserved.objects.filter(client=client_id).order_by('-check_in')

Notice the - before check_in.

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