# documentación de Django - 1.10.7

# Providing initial data for models

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 fixtures or migrations.

## Providing initial data with 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.

As an example, though, here’s what a fixture for a simple `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.

Loading data is easy: just call `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 files

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.

Ver también

Fixtures are also used by the testing framework to help set up a consistent test environment.

## Providing initial data with migrations

If you want to automatically load initial data for an app, don’t use fixtures. Instead, create a migration for your application with `RunPython` or `RunSQL` operations.