mirror of
https://github.com/graphql-python/graphene-django.git
synced 2024-11-28 12:33:43 +03:00
394 lines
10 KiB
ReStructuredText
394 lines
10 KiB
ReStructuredText
Basic Tutorial
|
|
===========================================
|
|
|
|
Graphene Django has a number of additional features that are designed to make
|
|
working with Django easy. Our primary focus in this tutorial is to give a good
|
|
understanding of how to connect models from Django ORM to Graphene object types.
|
|
|
|
Set up the Django project
|
|
-------------------------
|
|
|
|
We will set up the project, create the following:
|
|
|
|
- A Django project called ``cookbook``
|
|
- An app within ``cookbook`` called ``ingredients``
|
|
|
|
.. code:: bash
|
|
|
|
# Create the project directory
|
|
mkdir cookbook
|
|
cd cookbook
|
|
|
|
# Create a virtualenv to isolate our package dependencies locally
|
|
virtualenv env
|
|
source env/bin/activate # On Windows use `env\Scripts\activate`
|
|
|
|
# Install Django and Graphene with Django support
|
|
pip install django graphene_django
|
|
|
|
# Set up a new project with a single application
|
|
django-admin startproject cookbook . # Note the trailing '.' character
|
|
cd cookbook
|
|
django-admin startapp ingredients
|
|
|
|
Now sync your database for the first time:
|
|
|
|
.. code:: bash
|
|
|
|
python manage.py migrate
|
|
|
|
Let's create a few simple models...
|
|
|
|
Defining our models
|
|
^^^^^^^^^^^^^^^^^^^
|
|
|
|
Let's get started with these models:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/ingredients/models.py
|
|
from django.db import models
|
|
|
|
class Category(models.Model):
|
|
name = models.CharField(max_length=100)
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
class Ingredient(models.Model):
|
|
name = models.CharField(max_length=100)
|
|
notes = models.TextField()
|
|
category = models.ForeignKey(
|
|
Category, related_name="ingredients", on_delete=models.CASCADE
|
|
)
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
Add ingredients as INSTALLED_APPS:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/settings.py
|
|
|
|
INSTALLED_APPS = [
|
|
...
|
|
# Install the ingredients app
|
|
"cookbook.ingredients",
|
|
]
|
|
|
|
|
|
Don't forget to create & run migrations:
|
|
|
|
.. code:: bash
|
|
|
|
python manage.py makemigrations
|
|
python manage.py migrate
|
|
|
|
|
|
Load some test data
|
|
^^^^^^^^^^^^^^^^^^^
|
|
|
|
Now is a good time to load up some test data. The easiest option will be
|
|
to `download the
|
|
ingredients.json <https://raw.githubusercontent.com/graphql-python/graphene-django/master/examples/cookbook/cookbook/ingredients/fixtures/ingredients.json>`__
|
|
fixture and place it in
|
|
``cookbook/ingredients/fixtures/ingredients.json``. You can then run the
|
|
following:
|
|
|
|
.. code:: bash
|
|
|
|
python manage.py loaddata ingredients
|
|
|
|
Installed 6 object(s) from 1 fixture(s)
|
|
|
|
Alternatively you can use the Django admin interface to create some data
|
|
yourself. You'll need to run the development server (see below), and
|
|
create a login for yourself too (``python manage.py createsuperuser``).
|
|
|
|
Register models with admin panel:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/ingredients/admin.py
|
|
from django.contrib import admin
|
|
from cookbook.ingredients.models import Category, Ingredient
|
|
|
|
admin.site.register(Category)
|
|
admin.site.register(Ingredient)
|
|
|
|
|
|
Hello GraphQL - Schema and Object Types
|
|
---------------------------------------
|
|
|
|
In order to make queries to our Django project, we are going to need few things:
|
|
|
|
* Schema with defined object types
|
|
* A view, taking queries as input and returning the result
|
|
|
|
GraphQL presents your objects to the world as a graph structure rather
|
|
than a more hierarchical structure to which you may be accustomed. In
|
|
order to create this representation, Graphene needs to know about each
|
|
*type* of object which will appear in the graph.
|
|
|
|
This graph also has a *root type* through which all access begins. This
|
|
is the ``Query`` class below.
|
|
|
|
To create GraphQL types for each of our Django models, we are going to subclass the ``DjangoObjectType`` class which will automatically define GraphQL fields that correspond to the fields on the Django models.
|
|
|
|
After we've done that, we will list those types as fields in the ``Query`` class.
|
|
|
|
Create ``cookbook/schema.py`` and type the following:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/schema.py
|
|
import graphene
|
|
from graphene_django import DjangoObjectType
|
|
|
|
from cookbook.ingredients.models import Category, Ingredient
|
|
|
|
class CategoryType(DjangoObjectType):
|
|
class Meta:
|
|
model = Category
|
|
fields = ("id", "name", "ingredients")
|
|
|
|
class IngredientType(DjangoObjectType):
|
|
class Meta:
|
|
model = Ingredient
|
|
fields = ("id", "name", "notes", "category")
|
|
|
|
class Query(graphene.ObjectType):
|
|
all_ingredients = graphene.List(IngredientType)
|
|
category_by_name = graphene.Field(CategoryType, name=graphene.String(required=True))
|
|
|
|
def resolve_all_ingredients(root, info):
|
|
# We can easily optimize query count in the resolve method
|
|
return Ingredient.objects.select_related("category").all()
|
|
|
|
def resolve_category_by_name(root, info, name):
|
|
try:
|
|
return Category.objects.get(name=name)
|
|
except Category.DoesNotExist:
|
|
return None
|
|
|
|
schema = graphene.Schema(query=Query)
|
|
|
|
You can think of this as being something like your top-level ``urls.py``
|
|
file.
|
|
|
|
Testing everything so far
|
|
-------------------------
|
|
|
|
We are going to do some configuration work, in order to have a working Django where we can test queries, before we move on, updating our schema.
|
|
|
|
Update settings
|
|
^^^^^^^^^^^^^^^
|
|
|
|
Next, install your app and GraphiQL in your Django project. GraphiQL is
|
|
a web-based integrated development environment to assist in the writing
|
|
and executing of GraphQL queries. It will provide us with a simple and
|
|
easy way of testing our cookbook project.
|
|
|
|
Add ``graphene_django`` to ``INSTALLED_APPS`` in ``cookbook/settings.py``:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/settings.py
|
|
|
|
INSTALLED_APPS = [
|
|
...
|
|
"graphene_django",
|
|
]
|
|
|
|
And then add the ``SCHEMA`` to the ``GRAPHENE`` config in ``cookbook/settings.py``:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/settings.py
|
|
|
|
GRAPHENE = {
|
|
"SCHEMA": "cookbook.schema.schema"
|
|
}
|
|
|
|
Alternatively, we can specify the schema to be used in the urls definition,
|
|
as explained below.
|
|
|
|
Creating GraphQL and GraphiQL views
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
Unlike a RESTful API, there is only a single URL from which GraphQL is
|
|
accessed. Requests to this URL are handled by Graphene's ``GraphQLView``
|
|
view.
|
|
|
|
This view will serve as GraphQL endpoint. As we want to have the
|
|
aforementioned GraphiQL we specify that on the parameters with ``graphiql=True``.
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/urls.py
|
|
|
|
from django.contrib import admin
|
|
from django.urls import path
|
|
from django.views.decorators.csrf import csrf_exempt
|
|
|
|
from graphene_django.views import GraphQLView
|
|
|
|
urlpatterns = [
|
|
path("admin/", admin.site.urls),
|
|
path("graphql", csrf_exempt(GraphQLView.as_view(graphiql=True))),
|
|
]
|
|
|
|
|
|
If we didn't specify the target schema in the Django settings file
|
|
as explained above, we can do so here using:
|
|
|
|
.. code:: python
|
|
|
|
# cookbook/urls.py
|
|
|
|
from django.contrib import admin
|
|
from django.urls import path
|
|
from django.views.decorators.csrf import csrf_exempt
|
|
|
|
from graphene_django.views import GraphQLView
|
|
|
|
from cookbook.schema import schema
|
|
|
|
urlpatterns = [
|
|
path("admin/", admin.site.urls),
|
|
path("graphql", csrf_exempt(GraphQLView.as_view(graphiql=True, schema=schema))),
|
|
]
|
|
|
|
|
|
|
|
Testing our GraphQL schema
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
We're now ready to test the API we've built. Let's fire up the server
|
|
from the command line.
|
|
|
|
.. code:: bash
|
|
|
|
python manage.py runserver
|
|
|
|
Performing system checks...
|
|
Django version 3.0.7, using settings 'cookbook.settings'
|
|
Starting development server at http://127.0.0.1:8000/
|
|
Quit the server with CONTROL-C.
|
|
|
|
Go to `localhost:8000/graphql <http://localhost:8000/graphql>`__ and
|
|
type your first query!
|
|
|
|
.. code::
|
|
|
|
query {
|
|
allIngredients {
|
|
id
|
|
name
|
|
}
|
|
}
|
|
|
|
If you are using the provided fixtures, you will see the following response:
|
|
|
|
.. code::
|
|
|
|
{
|
|
"data": {
|
|
"allIngredients": [
|
|
{
|
|
"id": "1",
|
|
"name": "Eggs"
|
|
},
|
|
{
|
|
"id": "2",
|
|
"name": "Milk"
|
|
},
|
|
{
|
|
"id": "3",
|
|
"name": "Beef"
|
|
},
|
|
{
|
|
"id": "4",
|
|
"name": "Chicken"
|
|
}
|
|
]
|
|
}
|
|
}
|
|
|
|
|
|
Congratulations, you have created a working GraphQL server 🥳!
|
|
|
|
Note: Graphene `automatically camelcases <http://docs.graphene-python.org/en/latest/types/schema/#auto-camelcase-field-names>`__ all field names for better compatibility with JavaScript clients.
|
|
|
|
|
|
Getting relations
|
|
-----------------
|
|
|
|
Using the current schema we can query for relations too. This is where GraphQL becomes really powerful!
|
|
|
|
For example, we may want to get a specific categories and list all ingredients that are in that category.
|
|
|
|
We can do that with the following query:
|
|
|
|
.. code::
|
|
|
|
query {
|
|
categoryByName(name: "Dairy") {
|
|
id
|
|
name
|
|
ingredients {
|
|
id
|
|
name
|
|
}
|
|
}
|
|
}
|
|
|
|
This will give you (in case you are using the fixtures) the following result:
|
|
|
|
.. code::
|
|
|
|
{
|
|
"data": {
|
|
"categoryByName": {
|
|
"id": "1",
|
|
"name": "Dairy",
|
|
"ingredients": [
|
|
{
|
|
"id": "1",
|
|
"name": "Eggs"
|
|
},
|
|
{
|
|
"id": "2",
|
|
"name": "Milk"
|
|
}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
|
|
We can also list all ingredients and get information for the category they are in:
|
|
|
|
.. code::
|
|
|
|
query {
|
|
allIngredients {
|
|
id
|
|
name
|
|
category {
|
|
id
|
|
name
|
|
}
|
|
}
|
|
}
|
|
|
|
Summary
|
|
-------
|
|
|
|
As you can see, GraphQL is very powerful and integrating Django models allows you to get started with a working server quickly.
|
|
|
|
If you want to put things like ``django-filter`` and automatic pagination in action, you should continue with the :ref:`Relay tutorial`.
|
|
|
|
A good idea is to check the `Graphene <http://docs.graphene-python.org/en/latest/>`__
|
|
documentation so that you are familiar with it as well.
|