Django Rest Framework创建外键序列化器上下文对象为空？

时间：2018-03-02 08:37:32

标签： django django-rest-framework django-serializer

我正在努力为学校创建一个小django api。目前，当我尝试使用外键创建模型时遇到授权用户时遇到问题。这是我一直在尝试的代码 MODEL：

class JobListing(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
company_name = models.CharField(max_length=80)
job_position = models.CharField(max_length=50)
job_phone = models.CharField(max_length=10)
job_email = models.EmailField()
job_description = models.TextField()
job_schedule = models.CharField(max_length=500)
job_post_date = models.DateField(auto_now_add=True)

查看：

class CreatePostView(generics.CreateAPIView):
"""
API endpoint that allows a Job Post to be created
"""
#queryset = ''
authentication_classes = (TokenAuthentication,)
permission_classes = (IsAuthenticated,)
serializer_class = JobPostingSerializer

串行：

class JobPostingSerializer(serializers.ModelSerializer):
user = serializers.SerializerMethodField()

class Meta:
    model = JobListing
    fields = ('user', 'company_name', 'job_position', 'job_phone', 'job_email', 'job_description', 'job_schedule')

def create(self, validated_data):
    post = super().create(validated_data)
    post.save()
    return post

def get_user(self, instance):
    user = self.context['request'].user
    return user.id

URLS：

    urlpatterns = [
url(r'^', include(router.urls)),
url(r'^api-auth', include('rest_framework.urls', namespace='rest_framework')),
path('home/', views.Home.as_view(), name='home'),
path('login/', views.Login.as_view(), name='login'),
path('getUserDetail/', views.TestSimpleUserJsonAuth.as_view(), name='getUserDetail'),
path('getPosts/', views.getPosts.as_view(), name='getPosts'),
url(r'signup/', views.CreateUserView.as_view(), name='signup'),
url(r'createPost/', views.CreatePostView.as_view(), name='createPost')

我尝试了很多不同的变体，包括重写get context方法并尝试更改我正在使用的视图集。似乎没有什么能让它发挥作用。我现在看到的错误是

  

/ createPost /中的IntegrityError   NOT NULL约束失败：temploybackend_joblisting.user_id

     

请求方法：POST   请求网址：http://192.168.99.100:8000/createPost/

回溯：

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py" in execute
  303.         return Database.Cursor.execute(self, query, params)

The above exception (NOT NULL constraint failed: temploybackend_joblisting.user_id) was the direct cause of the following exception:

File "/usr/local/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
  35.             response = get_response(request)

File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  128.                 response = self.process_exception_by_middleware(e, request)

File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  126.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/usr/local/lib/python3.6/site-packages/django/views/decorators/csrf.py" in wrapped_view
  54.         return view_func(*args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/django/views/generic/base.py" in view
  69.             return self.dispatch(request, *args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py" in dispatch
  494.             response = self.handle_exception(exc)

File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py" in handle_exception
  454.             self.raise_uncaught_exception(exc)

File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py" in dispatch
  491.             response = handler(request, *args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/rest_framework/generics.py" in post
  192.         return self.create(request, *args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/rest_framework/mixins.py" in create
  21.         self.perform_create(serializer)

File "/usr/local/lib/python3.6/site-packages/rest_framework/mixins.py" in perform_create
  26.         serializer.save()

File "/usr/local/lib/python3.6/site-packages/rest_framework/serializers.py" in save
  214.             self.instance = self.create(validated_data)

File "/var/www/temploybackend/serializers.py" in create
  54.       post = super().create(validated_data)

File "/usr/local/lib/python3.6/site-packages/rest_framework/serializers.py" in create
  917.             instance = ModelClass.objects.create(**validated_data)

File "/usr/local/lib/python3.6/site-packages/django/db/models/manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py" in create
  417.         obj.save(force_insert=True, using=self.db)

File "/usr/local/lib/python3.6/site-packages/django/db/models/base.py" in save
  729.                        force_update=force_update, update_fields=update_fields)

File "/usr/local/lib/python3.6/site-packages/django/db/models/base.py" in save_base
  759.             updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)

File "/usr/local/lib/python3.6/site-packages/django/db/models/base.py" in _save_table
  842.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)

File "/usr/local/lib/python3.6/site-packages/django/db/models/base.py" in _do_insert
  880.                                using=using, raw=raw)

File "/usr/local/lib/python3.6/site-packages/django/db/models/manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py" in _insert
  1125.         return query.get_compiler(using=using).execute_sql(return_id)

File "/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in execute_sql
  1281.                 cursor.execute(sql, params)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
  100.             return super().execute(sql, params)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
  68.         return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute_with_wrappers
  77.         return executor(sql, params, many, context)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "/usr/local/lib/python3.6/site-packages/django/db/utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py" in _execute
  85.                 return self.cursor.execute(sql, params)

File "/usr/local/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py" in execute
  303.         return Database.Cursor.execute(self, query, params)

Exception Type: IntegrityError at /createPost/
Exception Value: NOT NULL constraint failed: temploybackend_joblisting.user_id

感谢您提供任何帮助！

1 个答案:

答案 0 :(得分：0)

SerializerMethodField是read_only字段，不在对象创建中使用。您需要将PrimaryKeyRelatedField替换为默认CurrentUserDefault：

class JobPostingSerializer(serializers.ModelSerializer):
    user = serializers.PrimaryKeyRelatedField(
        read_only=True,  
        default=serializers.CurrentUserDefault()
    )

    class Meta:
        model = JobListing
        fields = ('user', 'company_name', 'job_position', 'job_phone', 'job_email', 'job_description', 'job_schedule')

    def create(self, validated_data):
        post = super().create(validated_data)
        post.save()
        return post
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