Django 面试题与答案
问题 46. What types of exception classes are there in Django?
The following are the exception classes available in Django:
Exception | Description |
AppRegistryNotReady | Raised when we try to use models before the app loading process. |
ObjectDoesNotExist | Base class for DoesNotExist exceptions. |
EmptyResultSet | Raised if a query does not return any result. |
FieldDoesNotExist | Raised if the requested field does not exist. |
MultipleObjectsReturned | A query will raise this exception if only one object is expected, but multiple objects are returned. |
SuspiciousOperation | Raised when a suspicious operation has been performed by the user. |
PermissionDenied | Raised when a user does not have an appropriate permission to perform a specified action. |
ViewDoesNotExist | Raised by django.urls if the requested view does not exist. |
MiddlewareNotUsed | Raised if a middleware is not used in the server configuration. |
ImproperlyConfigured | Raised if Django is somehow improperly configured. |
FieldError | Raised if there is a problem with a model field. |
ValidationError | Raised if the data validation fails to form or model field validation. |
问题 47. What are the specific Django field class types?
Field class types specify the following:
- The database column type.
- The default HTML widget for availing while rendering a form field.
- The minimal validation requirements used in Django admin that helps in automatically generated forms.
问题 48. What are the different types of views available in Django?
The following are the two different types of views available in Django:
- Function-Based Views: It lets you import a view as a function
- Class-based Views: It is an object-oriented approach
问题 49. Which companies use Django?
The following is a list of some companies that use Django:
- PBS
- Mozilla
- The Washington Times
- Disqus, Bitbucket
- NextDoor
- YouTube
- DISCUS
问题 50. What is a model in Django?
A Model is specified as a Python class derived from the Model class. This model class is imported from the django.db.models library. The main concept of Django Models is to create objects for storing data from a user in a user-defined format.
The model class is a pre-defined class with lots of benefits. You can define the field with specific attributes as you can do in SQL, but the same can also be achieved in Python.
This class is parsed by Django ORM or backend engine, and there is no need to do anything related to a database, such as creating tables and defining fields afterward mapping the fields with the attribute of the class.
用户评价最有帮助的内容：
- What are the different applications of Django?
- What are view functions? Can you directly import a function within the URL?
- What is a model in Django?