{"title":"System check framework","version":"1.8","locale":"en","docname":"ref/checks","url":"/en/1.8/ref/checks/","canonical":"https://djangodocs.dev/en/1.8/ref/checks/","summary":"New in Django 1.7 The system check framework is a set of static checks for validating Django projects. It detects common problems and provides hints for how to fix…","html":"

System check frameworkLink to this heading#

\n\n

The system check framework is a set of static checks for validating Django\nprojects. It detects common problems and provides hints for how to fix them.\nThe framework is extensible so you can easily add your own checks.

\n

For details on how to add your own checks and integrate them with Django’s\nsystem checks, see the System check topic guide.

\n
\n

API ReferenceLink to this heading#

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\n

CheckMessageLink to this heading#

\n
\n
\nclass CheckMessage(level, msg, hint, obj=None, id=None)Link to this definition#
\n
\n\n

The warnings and errors raised by system checks must be instances of\nCheckMessage. An instance encapsulates a single reportable error or\nwarning. It also provides context and hints applicable to the message, and a\nunique identifier that is used for filtering purposes.

\n

Constructor arguments are:

\n
\n
level

The severity of the message. Use one of the predefined values: DEBUG,\nINFO, WARNING, ERROR, CRITICAL. If the level is greater or\nequal to ERROR, then Django will prevent management commands from\nexecuting. Messages with level lower than ERROR (i.e. warnings) are\nreported to the console, but can be silenced.

\n
\n
msg

A short (less than 80 characters) string describing the problem. The string\nshould not contain newlines.

\n
\n
hint

A single-line string providing a hint for fixing the problem. If no hint\ncan be provided, or the hint is self-evident from the error message, the\nhint can be omitted, or a value of None can be used.

\n
\n
obj

Optional. An object providing context for the message (for example, the\nmodel where the problem was discovered). The object should be a model,\nfield, or manager or any other object that defines __str__ method (on\nPython 2 you need to define __unicode__ method). The method is used\nwhile reporting all messages and its result precedes the message.

\n
\n
id

Optional string. A unique identifier for the issue. Identifiers should\nfollow the pattern applabel.X001, where X is one of the letters\nCEWID, indicating the message severity (C for criticals, E for\nerrors and so). The number can be allocated by the application, but should\nbe unique within that application.

\n
\n
\n

There are subclasses to make creating messages with common levels easier. When\nusing them you can omit the level argument because it is implied by the\nclass name.

\n
\n
\nclass Debug(msg, hint, obj=None, id=None)Link to this definition#
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\n\n
\n
\nclass Info(msg, hint, obj=None, id=None)Link to this definition#
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\n\n
\n
\nclass Warning(msg, hint, obj=None, id=None)Link to this definition#
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\n\n
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\nclass Error(msg, hint, obj=None, id=None)Link to this definition#
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\n\n
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\nclass Critical(msg, hint, obj=None, id=None)Link to this definition#
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\n\n
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Builtin checksLink to this heading#

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Builtin tagsLink to this heading#

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Django’s system checks are organized using the following tags:

\n\n

Some checks may be registered with multiple tags.

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\n
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Core system checksLink to this heading#

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\n

ModelsLink to this heading#

\n
    \n

  • models.E001: <swappable> is not of the form app_label.app_name.

    • \n

  • models.E002: <SETTING> references <model>, which has not been\ninstalled, or is abstract.

    • \n

  • models.E003: The model has two many-to-many relations through the\nintermediate model <app_label>.<model>.

    • \n

  • models.E004: id can only be used as a field name if the field also\nsets primary_key=True.

    • \n

  • models.E005: The field <field name> from parent model <model>\nclashes with the field <field name> from parent model <model>.

    • \n

  • models.E006: The field clashes with the field <field name> from model\n<model>.

    • \n

  • models.E007: Field <field name> has column name <column name>\nthat is used by another field.

    • \n

  • models.E008: index_together must be a list or tuple.

    • \n

  • models.E009: All index_together elements must be lists or tuples.

    • \n

  • models.E010: unique_together must be a list or tuple.

    • \n

  • models.E011: All unique_together elements must be lists or tuples.

    • \n

  • models.E012: index_together/unique_together refers to the\nnon-existent field <field name>.

    • \n

  • models.E013: index_together/unique_together refers to a\nManyToManyField <field name>, but ManyToManyFields are not\nsupported for that option.

    • \n

  • models.E014: ordering must be a tuple or list (even if you want to\norder by only one field).

    • \n

  • models.E015: ordering refers to the non-existent field\n<field name>.

    • \n

  • models.E016: index_together/unique_together refers to field\n<field_name> which is not local to model <model>.

    • \n

  • models.E017: Proxy model <model> contains model fields.

    • \n

  • models.E018: Autogenerated column name too long for field <field>.\nMaximum length is <maximum length> for database <alias>.

    • \n

  • models.E019: Autogenerated column name too long for M2M field\n<M2M field>. Maximum length is <maximum length> for database\n<alias>.

    • \n

  • models.E020: The <model>.check() class method is currently overridden.

    • \n
\n
\n
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FieldsLink to this heading#

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    \n

  • fields.E001: Field names must not end with an underscore.

    • \n

  • fields.E002: Field names must not contain "__".

    • \n

  • fields.E003: pk is a reserved word that cannot be used as a field\nname.

    • \n

  • fields.E004: choices must be an iterable (e.g., a list or tuple).

    • \n

  • fields.E005: choices must be an iterable returning (actual value,\nhuman readable name) tuples.

    • \n

  • fields.E006: db_index must be None, True or False.

    • \n

  • fields.E007: Primary keys must not have null=True.

    • \n

  • fields.E100: AutoFields must set primary_key=True.

    • \n

  • fields.E110: BooleanFields do not accept null values.

    • \n

  • fields.E120: CharFields must define a max_length attribute.

    • \n

  • fields.E121: max_length must be a positive integer.

    • \n

  • fields.W122: max_length is ignored when used with IntegerField.

    • \n

  • fields.E130: DecimalFields must define a decimal_places attribute.

    • \n

  • fields.E131: decimal_places must be a non-negative integer.

    • \n

  • fields.E132: DecimalFields must define a max_digits attribute.

    • \n

  • fields.E133: max_digits must be a non-negative integer.

    • \n

  • fields.E134: max_digits must be greater or equal to decimal_places.

    • \n

  • fields.E140: FilePathFields must have either allow_files or\nallow_folders set to True.

    • \n

  • fields.E150: GenericIPAddressFields cannot accept blank values if\nnull values are not allowed, as blank values are stored as nulls.

    • \n

  • fields.E160: The options auto_now, auto_now_add, and default\nare mutually exclusive. Only one of these options may be present.

    • \n

  • fields.W161: Fixed default value provided.

    • \n

  • fields.W900: IPAddressField has been deprecated. Support for it\n(except in historical migrations) will be removed in Django 1.9.

    • \n
\n
\n
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File FieldsLink to this heading#

\n
    \n

  • fields.E200: unique is not a valid argument for a FileField.

    • \n

  • fields.E201: primary_key is not a valid argument for a FileField.

    • \n

  • fields.E210: Cannot use ImageField because Pillow is not installed.

    • \n
\n
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Related FieldsLink to this heading#

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    \n

  • fields.E300: Field defines a relation with model <model>, which is\neither not installed, or is abstract.

    • \n

  • fields.E301: Field defines a relation with the model <model> which\nhas been swapped out.

    • \n

  • fields.E302: Accessor for field <field name> clashes with field\n<field name>.

    • \n

  • fields.E303: Reverse query name for field <field name> clashes with\nfield <field name>.

    • \n

  • fields.E304: Field name <field name> clashes with accessor for\n<field name>.

    • \n

  • fields.E305: Field name <field name> clashes with reverse query name\nfor <field name>.

    • \n

  • fields.E306: Related name must be a valid Python identifier or end with\na '+'.

    • \n

  • fields.E310: None of the fields <field1>, <field2>, … on model\n<model> have a unique=True constraint.

    • \n

  • fields.E311: <model> must set unique=True because it is\nreferenced by a ForeignKey.

    • \n

  • fields.E320: Field specifies on_delete=SET_NULL, but cannot be null.

    • \n

  • fields.E321: The field specifies on_delete=SET_DEFAULT, but has no\ndefault value.

    • \n

  • fields.E330: ManyToManyFields cannot be unique.

    • \n

  • fields.E331: Field specifies a many-to-many relation through model\n<model>, which has not been installed.

    • \n

  • fields.E332: Many-to-many fields with intermediate tables must not be\nsymmetrical.

    • \n

  • fields.E333: The model is used as an intermediate model by <model>,\nbut it has more than two foreign keys to <model>, which is ambiguous.\nYou must specify which two foreign keys Django should use via the\nthrough_fields keyword argument.

    • \n

  • fields.E334: The model is used as an intermediate model by <model>,\nbut it has more than one foreign key from <model>, which is ambiguous.\nYou must specify which foreign key Django should use via the\nthrough_fields keyword argument.

    • \n

  • fields.E335: The model is used as an intermediate model by <model>,\nbut it has more than one foreign key to <model>, which is ambiguous.\nYou must specify which foreign key Django should use via the\nthrough_fields keyword argument.

    • \n

  • fields.E336: The model is used as an intermediary model by <model>,\nbut it does not have foreign key to <model> or <model>.

    • \n

  • fields.E337: Field specifies through_fields but does not provide the\nnames of the two link fields that should be used for the relation through\n<model>.

    • \n

  • fields.E338: The intermediary model <through model> has no field\n<field name>.

    • \n

  • fields.E339: <model>.<field name> is not a foreign key to <model>.

    • \n

  • fields.W340: null has no effect on ManyToManyField.

    • \n

  • fields.W341: ManyToManyField does not support validators.

    • \n

  • fields.W342: Setting unique=True on a ForeignKey has the same\neffect as using a OneToOneField.

    • \n
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\n
\n

SignalsLink to this heading#

\n
    \n

  • signals.E001: <handler> was connected to the <signal> signal with\na lazy reference to the <model> sender, which has not been installed.

    • \n
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Backwards CompatibilityLink to this heading#

\n

The following checks are performed to warn the user of any potential problems\nthat might occur as a result of a version upgrade.

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    \n

  • 1_6.W001: Some project unit tests may not execute as expected. This\ncheck was removed in Django 1.8 due to false positives.

    • \n

  • 1_6.W002: BooleanField does not have a default value. This\ncheck was removed in Django 1.8 due to false positives.

    • \n

  • 1_7.W001: Django 1.7 changed the global defaults for the\nMIDDLEWARE_CLASSES.\ndjango.contrib.sessions.middleware.SessionMiddleware,\ndjango.contrib.auth.middleware.AuthenticationMiddleware, and\ndjango.contrib.messages.middleware.MessageMiddleware were removed from\nthe defaults. If your project needs these middleware then you should\nconfigure this setting.

    • \n

  • 1_8.W001: The standalone TEMPLATE_* settings were deprecated in\nDjango 1.8 and the TEMPLATES dictionary takes precedence. You must\nput the values of the following settings into your defaults TEMPLATES\ndict: TEMPLATE_DIRS, ALLOWED_INCLUDE_ROOTS,\nTEMPLATE_CONTEXT_PROCESSORS, TEMPLATE_DEBUG,\nTEMPLATE_LOADERS, TEMPLATE_STRING_IF_INVALID.

    • \n
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AdminLink to this heading#

\n

Admin checks are all performed as part of the admin tag.

\n

The following checks are performed on any\nModelAdmin (or subclass) that is registered\nwith the admin site:

\n\n
\n

ModelAdminLink to this heading#

\n

The following checks are performed on any\nModelAdmin that is registered\nwith the admin site:

\n
    \n

  • admin.E101: The value of save_as must be a boolean.

    • \n

  • admin.E102: The value of save_on_top must be a boolean.

    • \n

  • admin.E103: The value of inlines must be a list or tuple.

    • \n

  • admin.E104: <InlineModelAdmin class> must inherit from\nBaseModelAdmin.

    • \n

  • admin.E105: <InlineModelAdmin class> must have a model attribute.

    • \n

  • admin.E106: The value of <InlineModelAdmin class>.model must be a\nModel.

    • \n

  • admin.E107: The value of list_display must be a list or tuple.

    • \n

  • admin.E108: The value of list_display[n] refers to <label>,\nwhich is not a callable, an attribute of <ModelAdmin class>, or an\nattribute or method on <model>.

    • \n

  • admin.E109: The value of list_display[n] must not be a\nManyToManyField.

    • \n

  • admin.E110: The value of list_display_links must be a list, a tuple,\nor None.

    • \n

  • admin.E111: The value of list_display_links[n] refers to <label>,\nwhich is not defined in list_display.

    • \n

  • admin.E112: The value of list_filter must be a list or tuple.

    • \n

  • admin.E113: The value of list_filter[n] must inherit from\nListFilter.

    • \n

  • admin.E114: The value of list_filter[n] must not inherit from\nFieldListFilter.

    • \n

  • admin.E115: The value of list_filter[n][1] must inherit from\nFieldListFilter.

    • \n

  • admin.E116: The value of list_filter[n] refers to <label>,\nwhich does not refer to a Field.

    • \n

  • admin.E117: The value of list_select_related must be a boolean,\ntuple or list.

    • \n

  • admin.E118: The value of list_per_page must be an integer.

    • \n

  • admin.E119: The value of list_max_show_all must be an integer.

    • \n

  • admin.E120: The value of list_editable must be a list or tuple.

    • \n

  • admin.E121: The value of list_editable[n] refers to <label>,\nwhich is not an attribute of <model>.

    • \n

  • admin.E122: The value of list_editable[n] refers to <label>,\nwhich is not contained in list_display.

    • \n

  • admin.E123: The value of list_editable[n] cannot be in both\nlist_editable and list_display_links.

    • \n

  • admin.E124: The value of list_editable[n] refers to the first field\nin list_display (<label>), which cannot be used unless\nlist_display_links is set.

    • \n

  • admin.E125: The value of list_editable[n] refers to <field name>,\nwhich is not editable through the admin.

    • \n

  • admin.E126: The value of search_fields must be a list or tuple.

    • \n

  • admin.E127: The value of date_hierarchy refers to <field name>,\nwhich is not an attribute of <model>.

    • \n

  • admin.E128: The value of date_hierarchy must be a DateField or\nDateTimeField.

    • \n
\n
\n
\n

InlineModelAdminLink to this heading#

\n

The following checks are performed on any\nInlineModelAdmin that is registered as an\ninline on a ModelAdmin.

\n
    \n

  • admin.E201: Cannot exclude the field <field name>, because it is the\nforeign key to the parent model <app_label>.<model>.

    • \n

  • admin.E202: <model> has no ForeignKey to <parent model>./\n<model> has more than one ForeignKey to <parent model>.

    • \n

  • admin.E203: The value of extra must be an integer.

    • \n

  • admin.E204: The value of max_num must be an integer.

    • \n

  • admin.E205: The value of min_num must be an integer.

    • \n

  • admin.E206: The value of formset must inherit from\nBaseModelFormSet.

    • \n
\n
\n
\n

GenericInlineModelAdminLink to this heading#

\n

The following checks are performed on any\nGenericInlineModelAdmin that is\nregistered as an inline on a ModelAdmin.

\n
    \n

  • admin.E301: 'ct_field' references <label>, which is not a field\non <model>.

    • \n

  • admin.E302: 'ct_fk_field' references <label>, which is not a\nfield on <model>.

    • \n

  • admin.E303: <model> has no GenericForeignKey.

    • \n

  • admin.E304: <model> has no GenericForeignKey using content type\nfield <field name> and object ID field <field name>.

    • \n
\n
\n
\n
\n

AuthLink to this heading#

\n\n
\n
\n

Content TypesLink to this heading#

\n

The following checks are performed when a model contains a\nGenericForeignKey or\nGenericRelation:

\n\n
\n
\n

SecurityLink to this heading#

\n

The security checks do not make your site secure. They do not audit code, do\nintrusion detection, or do anything particularly complex. Rather, they help\nperform an automated, low-hanging-fruit checklist. They help you remember the\nsimple things that improve your site’s security.

\n

Some of these checks may not be appropriate for your particular deployment\nconfiguration. For instance, if you do your HTTP to HTTPS redirection in a load\nbalancer, it’d be irritating to be constantly warned about not having enabled\nSECURE_SSL_REDIRECT. Use SILENCED_SYSTEM_CHECKS to\nsilence unneeded checks.

\n

The following checks will be run if you use the --deploy option\nof the check command:

\n\n
\n
\n

SitesLink to this heading#

\n

The following checks are performed on any model using a\nCurrentSiteManager:

\n\n
\n
\n

DatabaseLink to this heading#

\n
\n

MySQLLink to this heading#

\n

If you’re using MySQL, the following checks will be performed:

\n
    \n

  • mysql.E001: MySQL does not allow unique CharFields to have a\nmax_length > 255.

    • \n
\n
\n
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","rootId":"system-check-framework","toc":[{"title":"API Reference","anchor":"api-reference","children":[{"title":"CheckMessage","anchor":"checkmessage","children":[]}]},{"title":"Builtin checks","anchor":"builtin-checks","children":[{"title":"Builtin tags","anchor":"builtin-tags","children":[]},{"title":"Core system checks","anchor":"core-system-checks","children":[{"title":"Models","anchor":"models","children":[]},{"title":"Fields","anchor":"fields","children":[]},{"title":"File Fields","anchor":"file-fields","children":[]},{"title":"Related Fields","anchor":"related-fields","children":[]},{"title":"Signals","anchor":"signals","children":[]},{"title":"Backwards Compatibility","anchor":"backwards-compatibility","children":[]}]},{"title":"Admin","anchor":"admin","children":[{"title":"ModelAdmin","anchor":"modeladmin","children":[]},{"title":"InlineModelAdmin","anchor":"inlinemodeladmin","children":[]},{"title":"GenericInlineModelAdmin","anchor":"genericinlinemodeladmin","children":[]}]},{"title":"Auth","anchor":"auth","children":[]},{"title":"Content Types","anchor":"content-types","children":[]},{"title":"Security","anchor":"security","children":[]},{"title":"Sites","anchor":"sites","children":[]},{"title":"Database","anchor":"database","children":[{"title":"MySQL","anchor":"mysql","children":[]}]}]}],"breadcrumbs":[{"docname":"ref/index","title":"API Reference","url":"/en/1.8/ref/"}],"prev":{"docname":"ref/applications","title":"Applications","url":"/en/1.8/ref/applications/"},"next":{"docname":"ref/class-based-views/index","title":"Built-in class-based views API","url":"/en/1.8/ref/class-based-views/"},"formats":{"html":"/en/1.8/ref/checks/","markdown":"/en/1.8/ref/checks.md","json":"/en/1.8/ref/checks.json"},"source":"https://github.com/django/django/blob/stable/1.8.x/docs/ref/checks.txt","official":"https://docs.djangoproject.com/en/1.8/ref/checks/","inVersions":["dev","6.1","6.0","5.2","5.1","5.0","4.2","4.1","4.0","3.2","3.1","3.0","2.2","2.1","2.0","1.11","1.10","1.9","1.8"],"inLocales":["en"]}