Django-Rest-and-Graphql
# 1. Django Project Setup With virtual environment:
mkdir {project_name}.
To install virtual Environment
sudo apt-get install python3-venv
To create virtual env directory
python3 -m venv djangoenv
to activate virtual environment
source djangoenv/bin/activate
To deactivate virtual environment
deactivate
Now we are installing Django in our virtual Env
pip install django
To Create a new Project
django-admin startproject {project_name}
eg. django-admin startproject sample_project
This command is used to runsserver of django
python manage.py runserver
To create tables in database, by default we have a user table in django project
-
python manage.py migrate ```
After adding we to apply migrate.
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying auth.0012_alter_user_first_name_max_length... OK
Applying sessions.0001_initial... OK
Default this migration is apply on migrate
Now Our projects basic Setup is Done
This command is used to Create a Super user to access django default admin panel
python manage.py createsuperuser
To create a new application in our project
django-admin startapp {app_name}
After creating new app we have to add this app in installed_apps in settings.py file
----------------------------------------------------------------------------xxxxx---------------------------------------------------------------------------------
2. Django REST Framework Setup :
First we have install django rest framework in our Virtual Environment
to install django rest framework in our Virtual Environment
pip install djangorestframework.
We can check what we have installed in our env
pip freeze
we have to add rest_framework in installed apps settings.py file
-
INSTALLED_APPS = [ 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'employee', 'rest_framework', ]
DRF CRUD Operation .
Create Serializer.py file in app.
from rest_framework import serializers
from .models import Employee
class EmployeeSerializer(serializers.ModelSerializer):
class Meta:
model = Employee
fields = '__all__'
We are creating Crud Operation with APIview class based
-
Go in th views.py file
-
CRUD(Create, Retrieve, Update, Delete)
class EmployeesCrud(APIView):
"""
View to list all users in the system.
* Requires token authentication.
* Only admin users are able to access this view.
"""
def get_object(self, pk):
return Employee.objects.get(id=pk)
```
##### Creating class called EmployeeCrud and get_object method in it to get data
##### Retrieve:
5. ```
def get(self, request,pk=None, format=None):
"""
Return a list of all users.
"""
if pk is None:
usernames = Employee.objects.all()
print("usernames", usernames)
serializer = EmployeeSerializer(usernames, many=True)
return Response(serializer.data)
else:
employee = self.get_object(pk)
serializer = EmployeeSerializer(employee)
return Response(serializer.data)
with method we are creating fetch data api
Create:
def post(self, request, pk=None, format=None):
"""
create a New Employee
"""
serializer = EmployeeSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
This method is used to create a new Entry in a table called Employee
Update (Put, Patch):
def patch(self, request, pk):
"""
Update partially a New Employee
"""
employeemodel_object = self.get_object(pk)
serializer = EmployeeSerializer(employeemodel_object, data=request.data, partial=True) # set partial=True to update a data partially
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
def put(self, request, pk, format=None):
"""
update a Employee
"""
employee = self.get_object(pk)
serializer = EmployeeSerializer(employee, data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
These two method is used to update the Employee table entry, with Put method we update whole entry and with Patch Method we can update partial field update.
Delete:
def delete(self, request, pk, format=None):
"""
delete a Employee
"""
employee = self.get_object(pk)
employee.delete()
return Response(status=status.HTTP_204_NO_CONTENT)
This method is used to delete a Entry
After Creating Class and method we have to create a url for it .
9 . In urls.py
file of a Employee app
from employee import views
path('employee/', views.EmployeesCrud.as_view(), name='employeecrud'),
This url is used for without getting data by Id
path('employee/<int:pk>/', views.EmployeesCrud.as_view(), name='employeecrud')
this url is used when we update the particular data so we given ID for them so we created this url for that.
----------------------------------------------------------------------------xxxxx---------------------------------------------------------------------------------
3. Graphql Setup and Create Queries and mutations.
To install in your Virtual Environment and Locally also
pip install graphene-django
Add graphene django to the installed apps in settings.py file of your Django Project
INSTALLED_APPS = [
"django.contrib.staticfiles", # Required for GraphiQL
"graphene_django”
]
We need to add a graphql URL to the urls.py file of your django Project.
from django.urls import path
from graphene_django.views import GraphQLView
urlpatterns = [
path('admin/', admin.site.urls),
path('graphql/', GraphQLView.as_view(graphiql=True)),
# path("graphql", csrf_exempt(GraphQLView.as_view(graphiql=True))),
path('employee/', views.EmployeesCrud.as_view(), name='employeecrud'),
path('employee/<int:pk>/', views.EmployeesCrud.as_view(), name='employeecrud')
]
graphiql=True
to graphiql=False
if you do not want to use the GraphiQL API browser.
Change Finally, define the schema location for Graphene in the Settings.py file of your Django project:
GRAPHENE = {
"SCHEMA": "sample_project.schema.schema"
}
Now our Basic Setup is Done.
First we have to create the types.py file in our APP eg: employee in my Sample_project.
We define the type of Every model for which we want to add Query or Mutation
import graphene
from graphene_django import DjangoObjectType
from employee.models import Employee
class EmployeeType(DjangoObjectType):
class Meta:
model = Employee
fields = "__all__"
Now we create a schema.py file in our App . schema.py file is used to create a queries
import graphene
from employee.models import Employee
from employee import types
from employee.mutations import EmployeeCreate
class EmployeeList(graphene.ObjectType):
employees = graphene.List(types.EmployeeType)
employee = graphene.Field(types.EmployeeType, id=graphene.Int())
def resolve_employees(root, info):
return Employee.objects.all()
def resolve_employee(root, info, id):
try:
employee = Employee.objects.get(id=id)
return employee
except Employee.DoesNotExist:
return None
Now we create a mutations.py file in our App. To create a Mutations
from logging import error
import graphene
from employee import types
from employee.models import Employee
class EmployeeCreate(graphene.Mutation):
class Arguments:
reg_no = graphene.Int(required=True)
name = graphene.String(required=True)
email = graphene.String(required=True)
mobile = graphene.String(required=True)
errors = graphene.String()
employee = graphene.Field(types.EmployeeType)
@staticmethod
def mutate(root, info, reg_no, name, email, mobile):
try:
employee = Employee.objects.create(emplyee_regNo=reg_no,
emplyee_name=name,
employee_email=email,
employee_mobile=mobile
)
return EmployeeCreate(employee=employee, errors=None)
except:
return EmployeeCreate(employee=None, errors="Arguments not Valid")
After creating mutation we should add this mutation class in schema file like this :
class EmployeeMutations(graphene.ObjectType):
''' Add Customer related Mutations here '''
employee_create = EmployeeCreate.Field()
Now we create a new schema.py file in our project level so that we can run all queries and muatation.
import graphene
from graphene.types.mutation import Mutation
from employee import mutations
from employee.schema import EmployeeList
from employee.schema import EmployeeMutations
class Query(EmployeeList, graphene.ObjectType):
pass
class Mutations(EmployeeMutations):
pass
schema = graphene.Schema(Query, Mutations)
Now we can Run Our queries and mutations
- To run Queries and Mutation .
http://localhost:8000/graphql
Now To test Graphql API’s
In our app their is one tests.py file is already created so we write test cases here.
import json
from employee.models import Employee
from employee.schema import EmployeeList
from django.test import TestCase
from graphene.test import Client
from graphene_django.utils.testing import GraphQLTestCase
class MyFancyTestCase(GraphQLTestCase):
def test_some_query(self):
response = self.query(
'''
query {
employees {
id
emplyeeName
emplyeeRegno
}
}
''',
)
content = json.loads(response.content)
# This validates the status code and if you get errors
self.assertResponseNoErrors(response)
##### Add some more asserts if you like
...
def test_query_with_variables(self):
response = self.query(
'''
query employee($id: Int!){
employee(id: $id) {
id
emplyeeRegno
}
}
''',
variables={'id': 1}
)
content = json.loads(response.content)
# This validates the status code and if you get errors
self.assertResponseNoErrors(response)
You can run this test cases by:
python manage.py test
If your Test cases run successfully then out will be.
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
...
----------------------------------------------------------------------
Ran 3 tests in 0.013s
OK
Destroying test database for alias 'default'...
If any test case fail then error will be like:
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
..F
======================================================================
FAIL: test_some_query (employee.tests.MyFancyTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/erangle/Downloads/projects/sample_project/employee/tests.py", line 63, in test_some_query
self.assertResponseNoErrors(response)
File "/home/erangle/Downloads/projects/sample_project/sample_project/lib/python3.6/site-packages/graphene_django/utils/testing.py", line 117, in assertResponseNoErrors
self.assertEqual(resp.status_code, 200, msg or content)
AssertionError: 400 != 200 : {'errors': [{'message': 'Cannot query field "name" on type "EmployeeType".', 'locations': [{'line': 5, 'column': 21}]}]}
----------------------------------------------------------------------
Ran 3 tests in 0.016s
FAILED (failures=1)
Destroying test database for alias 'default'...
Test case for basic Models testing
class EmployeeTest(TestCase):
""" Test module for Employee model """
def setUp(self):
Employee.objects.create(emplyee_regNo=2,
emplyee_name="Ravi",
employee_email="[email protected]",
employee_mobile="7878788888")
Employee.objects.create(emplyee_regNo=3,
emplyee_name="ROom",
employee_email="[email protected]",
employee_mobile="7878788889")
def testEmployeeEmail(self):
employee2 = Employee.objects.get(emplyee_regNo=2)
employee3 = Employee.objects.get(emplyee_regNo=3)
self.assertEqual(
employee2.get_email(), "ravi email address is [email protected]")
self.assertEqual(
employee3.get_email(), "ROom email address is [email protected]")