Django raises some Django specific exceptions as well as many standard Python exceptions.
Django Core Exceptions¶
Django core exception classes are defined in django.core.exceptions.
ObjectDoesNotExist and DoesNotExist¶
- exception DoesNotExist¶
The DoesNotExist exception is raised when an object is not found for the given parameters of a query. Django provides a DoesNotExist exception as an attribute of each model class to identify the class of object that could not be found and to allow you to catch a particular model class with try/except.
- exception MultipleObjectsReturned¶
The MultipleObjectsReturned exception is raised by a query if only one object is expected, but multiple objects are returned. A base version of this exception is provided in django.core.exceptions; each model class contains a subclassed version that can be used to identify the specific object type that has returned multiple objects.
See get() for further information.
- exception SuspiciousOperation¶
The SuspiciousOperation exception is raised when a user has performed an operation that should be considered suspicious from a security perspective, such as tampering with a session cookie. Subclasses of SuspiciousOperation include:
- exception FieldError¶
The FieldError exception is raised when there is a problem with a model field. This can happen for several reasons:
- A field in a model clashes with a field of the same name from an abstract base class
- An infinite loop is caused by ordering
- A keyword cannot be parsed from the filter parameters
- A field cannot be determined from a keyword in the query parameters
- A join is not permitted on the specified field
- A field name is invalid
- A query contains invalid order_by arguments
URL Resolver exceptions¶
URL Resolver exceptions are defined in django.core.urlresolvers.
Database exceptions are provided in django.db.
Django wraps the standard database exceptions so that your Django code has a guaranteed common implementation of these classes.
- exception Error¶
- exception InterfaceError¶
- exception DatabaseError¶
- exception DataError¶
- exception OperationalError¶
- exception IntegrityError¶
- exception InternalError¶
- exception ProgrammingError¶
- exception NotSupportedError¶
The Django wrappers for database exceptions behave exactly the same as the underlying database exceptions. See PEP 249, the Python Database API Specification v2.0, for further information.
As per PEP 3134, a __cause__ attribute is set with the original (underlying) database exception, allowing access to any additional information provided. (Note that this attribute is available under both Python 2 and Python 3, although PEP 3134 normally only applies to Python 3.)
Previous versions of Django only wrapped DatabaseError and IntegrityError, and did not provide __cause__.
- exception models.ProtectedError¶
Http exceptions are provided in django.http.
Transaction exceptions are defined in django.db.transaction.