How Can I Combine Two or More QuerySets in a Django View?

James W.

The Problem

You know that Django allows for the creation of QuerySets from the database by making use of methods like filter() or exclude().

But can we create a QuerySet out of a combination of other QuerySets?

Say we wanted to create a QuerySet from data collected from two different models. The use of the filter() and exclude() methods would not help here.

Or we might be creating a QuerySet with complex inclusions and exclusions using the filter() and exclude() methods, and it would be simpler to create multiple QuerySets and then combine them into a single set.

The Solution

It is possible to combine QuerySets into another QuerySet, and they do not have to be from the same model.

The Python union operator can be used to combine QuerySets that belong to the same model.

Two or more QuerySets can be combined using the union operator with the following syntax:

model_combination = model_set1 | model_set2 | model_set3

You can also use the chain() method from the Itertools module, which allows you to combine two or more QuerySets from different models through concatenation.

from itertools import chain model_combination = list(chain(model_set1, model_set2))

Alternatively, you can use union() to combine two or more QuerySets from different models, passing all=TRUE if you want to allow duplicates.

model_combination = model_set1.union(model_set2, all=TRUE)

Further Reading

For some tips on working with Django on Sentry, have a look at these articles:

Loved by over 4 million developers and more than 90,000 organizations worldwide, Sentry provides code-level observability to many of the world’s best-known companies like Disney, Peloton, Cloudflare, Eventbrite, Slack, Supercell, and Rockstar Games. Each month we process billions of exceptions from the most popular products on the internet.

Share on Twitter
Bookmark this page
Ask a questionJoin the discussion

Related Answers

A better experience for your users. An easier life for your developers.

    TwitterGitHubDribbbleLinkedinDiscord
© 2024 • Sentry is a registered Trademark
of Functional Software, Inc.