Topic guide Making queries

To retrieve objects from your database, construct a QuerySet via a Manager on your model class. A QuerySet represents a collection of objects from your database. It can have zero, one or many filters.

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Topic guide Making queries

Sometimes you want to set a field to a particular value for all the objects in a QuerySet. You can do this with the update() method. For example: You can only set non-relation fields and ForeignKey fields using this method.

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Reference The Django admin site ModelAdmin objects

ModelAdmin.search_help_text : Set search_help_text to specify a descriptive text for the search box which will be displayed below it. ModelAdmin.show_full_result_count : Set show_full_result_count to control whether the full count of objects should be displayed on a filtered admin page (e.g.

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Topic guide Django shortcut functions

get_list_or_404(klass,*args,**kwargs)[source] aget_list_or_404(klass,*args,**kwargs) : Asynchronous version: aget_list_or_404()

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How-to

Django offers a wide variety of built-in lookups for filtering (for example, exact and icontains). This documentation explains how to write custom lookups and how to alter the working of existing lookups.

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How-to

Django offers a wide variety of built-in lookups for filtering (for example, exact and icontains). This documentation explains how to write custom lookups and how to alter the working of existing lookups.

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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).

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Index

… | | --- | --- | | - A (class in django.contrib.gis.measure) - aadd() (RelatedManager method) - aaggregate() (in module django.db.models.query.QuerySet) - aauthenticate() (in module django.contrib.auth) - (ModelBackend method) - (RemoteUserBackend method) - Abs (class in django.db.models.functions) - ABSOLUTE_URL_OVERRIDES - …

Index

| | | | --- | --- | | - each_context() (AdminSite method) - earliest() (in module django.db.models.query.QuerySet) - editable (Field attribute) - ELLIPSIS (Paginator attribute) - ellipsoid (SpatialReference attribute) - email (models.User attribute) - EMAIL_BACKEND - setting - EMAIL_FIELD …

Index

… - import_wkt() (SpatialReference method) - import_xml() (SpatialReference method) - ImproperlyConfigured - in - field lookup type - in_bulk() (in module django.db.models.query.QuerySet) - include - template tag - include (ExclusionConstraint attribute) - (Index attribute) - (UniqueConstraint attribute) - include() (in module …

Internals Django Deprecation Timeline

Calling QuerySet.aiterator() after prefetch_related() without providing a chunk_size will raise ValueError. The Extract and Trunc database functions will capture the current timezone in migrations when the tzinfo argument is omitted and USE_TZ is True.

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Tutorial Writing your first Django app, part 3

It’s a very common idiom to use get() and raise Http404 if the object doesn’t exist. Django provides a shortcut.

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Reference Generic display views

classdjango.views.generic.list.ListView : A page representing a list of objects. classdjango.views.generic.list.BaseListView : A base view for displaying a list of objects.

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Reference Date-based mixins

classDateMixin[source] : A mixin class providing common behavior for all date-based views.

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Reference Single object mixins

classdjango.views.generic.detail.SingleObjectMixin : Provides a mechanism for looking up an object associated with the current HTTP request.

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Reference Admin actions

Actions may limit their availability to users with specific permissions by wrapping the action function with the action() decorator and passing the permissions argument: The make_published() action will only be available to users that pass the ModelAdmin.has_change_permission() check when it …

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Reference ModelAdmin List Filters

… own list filter by subclassing django.contrib.admin.SimpleListFilter. You need to provide the title and parameter_name attributes, and override the lookups and queryset methods, e.g.: NOTE: As a convenience, the HttpRequest object is passed to the lookups > and queryset methods, for …

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Reference Geographic Database Functions

classGeometryDistance(expr1,expr2,**extra)[source] Availability: PostGIS Accepts two geographic fields or expressions and returns the distance between them. When used in an order_by() clause, it provides index-assisted nearest-neighbor result sets.

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Reference The sitemap framework

classSitemap[source] : A Sitemap class can define the following methods/attributes:

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Reference The sitemap framework

The sitemap framework provides a convenience class for a common case: classGenericSitemap(info_dict,priority=None,changefreq=None,protocol=None)[source] : The django.contrib.sitemaps.GenericSitemap class allows you to create a sitemap by passing it a dictionary which has to contain at least a queryset entry.

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