python – django order_by query set, ascending and descending

How can I order by descending my query set in django by date?

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

I just want to filter from descending all the Reserved by check_in date.

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

Notice the - before check_in.

Django Documentation

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()

for ascending order:

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

for descending order:

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

or

2.  Reserved.objects.filter(client=client_id).order_by('check_in')[::-1]

It works removing .all():

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

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',)

1. Ascending order

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

2. Descending order

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

- (hyphen) is used to indicate descending order here.

If for some reason you have null values you can use the F function like this:

from django.db.models import F

Reserved.objects.all().filter(client=client_id).order_by(F('check_in').desc(nulls_last=True))

So it will put last the null values. Documentation by Django: https://docs.djangoproject.com/en/stable/ref/models/expressions/#using-f-to-sort-null-values

Reserved.objects.filter(client=client_id).earliest('check_in')

Or alternatively

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

Here is the documentations for earliest() and latest()

This is working for me.

latestsetuplist = SetupTemplate.objects.order_by('-creationTime')[:10][::1]

67

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

‘-‘ is indicates Descending order and for Ascending order just give class attribute