What is Django Fixtures

It’s sometimes useful to pre-populate your database with hard-coded data when you’re first setting up an app. You can provide initial data with migrations or fixtures.

If you want to automatically load initial data for an app, create a data migration. Migrations are run when setting up the test database, so the data will be available there, subject to some limitations.

You can also provide data using fixtures, however, this data isn’t loaded automatically, except if you use TransactionTestCase.fixtures.

A fixture is a collection of data that Django knows how to import into a database. The most straightforward way of creating a fixture if you’ve already got some data is to use the manage.py dumpdata command. Or, you can write fixtures by hand; fixtures can be written as JSON, XML or YAML (with PyYAML installed) documents. The serialization documentation has more details about each of these supported serialization formats

a fixture for a Person model might look like in JSON:

[

  {

    "model": "myapp.person",

    "pk": 1,

    "fields": {

      "first_name": "John",

      "last_name": "Lennon"

    }

  },

  {

    "model": "myapp.person",

    "pk": 2,

    "fields": {

      "first_name": "Paul",

      "last_name": "McCartney"

    }

  }

]

And here’s that same fixture as YAML:

- model: myapp.person

  pk: 1

  fields:

    first_name: John

    last_name: Lennon

- model: myapp.person

  pk: 2

  fields:

    first_name: Paul

    last_name: McCartney

You’ll store this data in a fixtures directory inside your app.

You can load data by calling manage.py loaddata <fixturename>, where <fixturename> is the name of the fixture file you’ve created. Each time you run loaddata, the data will be read from the fixture and re-loaded into the database. Note this means that if you change one of the rows created by a fixture and then run loaddata again, you’ll wipe out any changes you’ve made.

Where Django finds fixture file

By default, Django looks in the fixtures directory inside each app for fixtures. You can set the FIXTURE_DIRS setting to a list of additional directories where Django should look.

When running manage.py loaddata, you can also specify a path to a fixture file, which overrides searching the usual directories.

References:

https://docs.djangoproject.com/en/3.2/howto/initial-data/