1 =================

     2 Django Exceptions

     3 =================

     4 

     5 

     6 Django raises some Django specific exceptions as well as many standard

     7 Python exceptions.

     8 

     9 Django-specific Exceptions

    10 ==========================

    11 

    12 .. module:: django.core.exceptions

    13     :synopsis: Django specific exceptions

    14 

    15 ObjectDoesNotExist and DoesNotExist

    16 -----------------------------------

    17 .. exception:: DoesNotExist

    18 .. exception:: ObjectDoesNotExist

    19 

    20     The :exc:`DoesNotExist` exception is raised when an object is not found

    21     for the given parameters of a query.

    22 

    23     :exc:`ObjectDoesNotExist` is defined in :mod:`django.core.exceptions`.

    24     :exc:`DoesNotExist` is a subclass of the base :exc:`ObjectDoesNotExist`

    25     exception that is provided on every model class as a way of

    26     identifying the specific type of object that could not be found.

    27 

    28     See :meth:`~django.db.models.QuerySet.get()` for further information

    29     on :exc:`ObjectDoesNotExist` and :exc:`DoesNotExist`.

    30 

    31 MultipleObjectsReturned

    32 -----------------------

    33 .. exception:: MultipleObjectsReturned

    34 

    35     The :exc:`MultipleObjectsReturned` exception is raised by a query if only

    36     one object is expected, but multiple objects are returned. A base version

    37     of this exception is provided in :mod:`django.core.exceptions`; each model

    38     class contains a subclassed version that can be used to identify the

    39     specific object type that has returned multiple objects.

    40 

    41     See :meth:`~django.db.models.QuerySet.get()` for further information.

    42 

    43 SuspiciousOperation

    44 -------------------

    45 .. exception:: SuspiciousOperation

    46 

    47     The :exc:`SuspiciousOperation` exception is raised when a user has performed

    48     an operation that should be considered suspicious from a security perspective,

    49     such as tampering with a session cookie.

    50 

    51 PermissionDenied

    52 ----------------

    53 .. exception:: PermissionDenied

    54 

    55     The :exc:`PermissionDenied` exception is raised when a user does not have

    56     permission to perform the action requested.

    57 

    58 ViewDoesNotExist

    59 ----------------

    60 .. exception:: ViewDoesNotExist

    61 

    62     The :exc:`ViewDoesNotExist` exception is raised by

    63     :mod:`django.core.urlresolvers` when a requested view does not exist.

    64 

    65 MiddlewareNotUsed

    66 -----------------

    67 .. exception:: MiddlewareNotUsed

    68 

    69     The :exc:`MiddlewareNotUsed` exception is raised when a middleware is not

    70     used in the server configuration.

    71 

    72 ImproperlyConfigured

    73 --------------------

    74 .. exception:: ImproperlyConfigured

    75 

    76     The :exc:`ImproperlyConfigured` exception is raised when Django is

    77     somehow improperly configured -- for example, if a value in ``settings.py``

    78     is incorrect or unparseable.

    79 

    80 FieldError

    81 ----------

    82 .. exception:: FieldError

    83 

    84     The :exc:`FieldError` exception is raised when there is a problem with a

    85     model field. This can happen for several reasons:

    86 

    87         - A field in a model clashes with a field of the same name from an

    88           abstract base class

    89         - An infinite loop is caused by ordering

    90         - A keyword cannot be parsed from the filter parameters

    91         - A field cannot be determined from a keyword in the query

    92           parameters

    93         - A join is not permitted on the specified field

    94         - A field name is invalid

    95         - A query contains invalid order_by arguments

    96 

    97 ValidationError

    98 ---------------

    99 .. exception:: ValidationError

   100 

   101     The :exc:`ValidationError` exception is raised when data fails form or

   102     model field validation. For more information about validation, see

   103     :doc:`Form and Field Validation </ref/forms/validation>`,

   104     :ref:`Model Field Validation <validating-objects>` and the

   105     :doc:`Validator Reference </ref/validators>`.

   106 

   107 Database Exceptions

   108 ===================

   109 

   110 Django wraps the standard database exceptions :exc:`DatabaseError` and

   111 :exc:`IntegrityError` so that your Django code has a guaranteed common

   112 implementation of these classes. These database exceptions are

   113 provided in :mod:`django.db`.

   114 

   115 The Django wrappers for database exceptions behave exactly the same as

   116 the underlying database exceptions. See `PEP 249 - Python Database API

   117 Specification v2.0`_ for further information.

   118 

   119 .. _`PEP 249 - Python Database API Specification v2.0`: http://www.python.org/dev/peps/pep-0249/

   120 

   121 Python Exceptions

   122 =================

   123 

   124 Django raises built-in Python exceptions when appropriate as well. See

   125 the Python `documentation`_ for further information on the built-in

   126 exceptions.

   127 

   128 .. _`documentation`: http://docs.python.org/lib/module-exceptions.html