Topic guide Testing tools Provided test case classes

classTransactionTestCase[source] TransactionTestCase inherits from SimpleTestCase to add some database-specific features: Resetting the database to a known state at the end of each test to ease testing and using the ORM. Database fixtures. Test skipping based on database backend features.

Topic guide Testing tools Test cases features

See assertJSONEqual() for further details. TransactionTestCase.assertQuerySetEqual(qs,values,transform=None,ordered=True,msg=None)[source] : Asserts that a queryset qs matches a particular iterable of values values. TransactionTestCase.assertNumQueries(num,func,*args,**kwargs)[source] : Asserts that when func is called with *args and **kwargs that num database queries are executed.

Internals Django Deprecation Timeline

Passing callable arguments to querysets will no longer be possible. BaseCommand.requires_model_validation will be removed in favor of requires_system_checks. Admin validators will be replaced by admin checks. The ModelAdmin.validator_class and default_validator_class attributes will be removed. ModelAdmin.validate() will be removed.

Reference

These functions are available from the django.contrib.postgres.aggregates module. They are described in more detail in the PostgreSQL docs. NOTE: All functions come without default aliases, so you must explicitly provide > one.

Reference PostgreSQL specific model fields HStoreFieldQuerying HStoreField

To query based on a given key, you can use that key as the lookup name: You can chain other lookups after key lookups: or use F() expressions to annotate a key value.

Reference

The classes documented below provide a way for users to use functions provided by the underlying database as annotations, aggregations, or filters in Django.

Reference Query Expressions

Both the querysets below are equivalent. >>> Company.objects.filter(num_employees__gt=F("num_chairs") * 2) >>> Company.objects.filter(num_employees__gt=F("num_chairs") + F("num_chairs")) # How many chairs are needed for each company to seat all employees? >>> company = ( ... Company.objects.filter(num_employees__gt=F("num_chairs")) ... .annotate(chairs_needed=F("num_employees") - F("num_chairs")) ... .first() ...

Reference Model field reference Field types

classDateTimeField(auto_now=False,auto_now_add=False,**options)[source] A date and time, represented in Python by a datetime.datetime instance. Takes the same extra arguments as DateField. The default form widget for this field is a single DateTimeInput. The admin uses two separate TextInput widgets with JavaScript shortcuts.

Reference Model field reference Field types

classUUIDField(**options)[source] A field for storing universally unique identifiers. Uses Python’s UUID class. When used on PostgreSQL and MariaDB 10.7+, this stores in a uuid datatype, otherwise in a char(32). Universally unique identifiers are a good alternative to AutoField for primary_key.

Reference Model field reference Relationship fieldsManyToManyField

ForeignKey.related_name : The name to use for the relation from the related object back to this one. It’s also the default value for related_query_name (the name to use for the reverse filter name from the target model).

Reference The Django template language

… relationship to a model called “task” you can loop through all comments attached to a given task like this: Similarly, QuerySets provide a count() method to count the number of objects they contain. Therefore, you can obtain a count of …

Topic guide Using mixins with class-based views

For example, a JSON mixin might look something like this: NOTE: Check out the Serializing Django objects documentation for more > information on how to correctly transform Django models and querysets into > JSON.

Topic guide Search Use Cases

Text-based fields have a selection of matching operations.

Topic guide Creating forms from models ModelForm

Consider this set of models: With these models, the ModelForm subclasses above would be roughly equivalent to this (the only difference being the save() method, which we’ll discuss in a moment.):

Index

… in django.forms) - DateMixin (class in django.views.generic.dates) - DateRangeField (class in django.contrib.postgres.fields) - (class in django.contrib.postgres.forms) - dates() (in module django.db.models.query.QuerySet) - DATETIME_FORMAT - setting - DATETIME_INPUT_FORMATS - setting - DateTimeField (class in django.db.models) - (class in django.forms) - DateTimeInput …

Index

… (class in django.core.files.storage) - FileUploadHandler (class in django.core.files.uploadhandler) - filter - template tag - filter() (django.template.Library method) - (in module django.db.models.query.QuerySet) - filter_horizontal (ModelAdmin attribute) - filter_vertical (ModelAdmin attribute) - filterable (Expression attribute) - FilteredRelation (class in django.db.models) - final_catch_all_view …

Index

… (django.views.generic.detail.BaseDetailView method) - (django.views.generic.edit.BaseCreateView method) - (django.views.generic.edit.BaseUpdateView method) - (django.views.generic.edit.ProcessFormView method) - (django.views.generic.list.BaseListView method) - (HttpResponse method) - (in module django.db.models.query.QuerySet) - (QueryDict method) - get_absolute_url() (Model method) - (models.FlatPage method) - get_accessed_time() (Storage method) - get_actions() (ModelAdmin method) - …

Index

… LANGUAGES - setting - languages (Sitemap attribute) - LANGUAGES_BIDI - setting - last - template filter - last() (in module django.db.models.query.QuerySet) - last_login (models.User attribute) - last_modified() (in module django.views.decorators.http) - last_name (models.User attribute) - lastmod (Sitemap attribute) - LastValue …

Index

… attribute) - non_atomic_requests() (in module django.db.transaction) | - NON_FIELD_ERRORS (in module django.core.exceptions) - non_field_errors() (Form method) - none() (in module django.db.models.query.QuerySet) - noop (RunSQL attribute) - noop() (RunPython static method) - NoReverseMatch - normalize() (GEOSGeometry method) - normalize_email() (models.BaseUserManager class …

Index

… on_delete (ForeignKey attribute) - one_to_many (Field attribute) - one_to_one (Field attribute) - OneToOneField (class in django.db.models) - only() (in module django.db.models.query.QuerySet) - OpClass (class in django.contrib.postgres.indexes) - opclasses (Index attribute) - (UniqueConstraint attribute) - open() (FieldFile method) - (File method) …