Ticket #15558: 15558_queryset.diff
| File 15558_queryset.diff, 6.2 KB (added by , 14 years ago) |
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docs/ref/models/querysets.txt
2 2 QuerySet API reference 3 3 ====================== 4 4 5 .. currentmodule:: django.db.models. QuerySet5 .. currentmodule:: django.db.models.query 6 6 7 7 This document describes the details of the ``QuerySet`` API. It builds on the 8 8 material presented in the :doc:`model </topics/db/models>` and :doc:`database … … 120 120 ============ 121 121 122 122 Though you usually won't create one manually -- you'll go through a 123 :class:`Manager` -- here's the formal declaration of a ``QuerySet``: 123 :class:`~django.db.models.Manager` -- here's the formal declaration of a 124 ``QuerySet``: 124 125 125 .. class:: QuerySet([model=None ])126 .. class:: QuerySet([model=None, query=None, using=None]) 126 127 127 Usually when you'll interact with a ``QuerySet`` you'll use it by :ref:`chaining 128 filters <chaining-filters>`. To make this work, most ``QuerySet`` methods return new querysets. 128 Usually when you'll interact with a ``QuerySet`` you'll use it by 129 :ref:`chaining filters <chaining-filters>`. To make this work, most 130 ``QuerySet`` methods return new querysets. These methods are covered in 131 detail later in this section. 129 132 133 The ``QuerySet`` class has two public attributes you can use for 134 introspection: 135 136 .. attribute:: ordered 137 138 ``True`` if the ``QuerySet`` is ordered -- i.e. has an order_by() 139 clause or a default ordering on the model. ``False`` otherwise. 140 141 .. attribute:: db 142 143 The database that will be used if this query is executed now. 144 145 .. currentmodule:: django.db.models.query.QuerySet 146 130 147 Methods that return new QuerySets 131 148 --------------------------------- 132 149 … … 285 302 ordering, call ``order_by()`` with no parameters. 286 303 287 304 You can tell if a query is ordered or not by checking the 288 :attr:` QuerySet.ordered` attribute, which will be ``True`` if the305 :attr:`.QuerySet.ordered` attribute, which will be ``True`` if the 289 306 ``QuerySet`` has been ordered in any way. 290 307 291 308 reverse … … 999 1016 elsewhere, but all it means is that a new object will always be created. 1000 1017 Normally you won't need to worry about this. However, if your model contains a 1001 1018 manual primary key value that you set and if that value already exists in the 1002 database, a call to ``create()`` will fail with an :exc:`IntegrityError` since1003 primary keys must be unique. So remember to be prepared to handle the exception 1004 if you are using manual primary keys.1019 database, a call to ``create()`` will fail with an 1020 :exc:`~django.db.IntegrityError` since primary keys must be unique. So remember 1021 to be prepared to handle the exception if you are using manual primary keys. 1005 1022 1006 1023 get_or_create 1007 1024 ~~~~~~~~~~~~~ … … 1197 1214 1198 1215 .. versionadded:: 1.2 1199 1216 1200 Returns ``True`` if the :class:` QuerySet` contains any results, and ``False``1217 Returns ``True`` if the :class:`.QuerySet` contains any results, and ``False`` 1201 1218 if not. This tries to perform the query in the simplest and fastest way 1202 1219 possible, but it *does* execute nearly the same query. This means that calling 1203 :meth:` QuerySet.exists()` is faster than ``bool(some_query_set)``, but not by1220 :meth:`.QuerySet.exists` is faster than ``bool(some_query_set)``, but not by 1204 1221 a large degree. If ``some_query_set`` has not yet been evaluated, but you know 1205 1222 that it will be at some point, then using ``some_query_set.exists()`` will do 1206 1223 more overall work (an additional query) than simply using … … 1213 1230 1214 1231 Performs an SQL update query for the specified fields, and returns 1215 1232 the number of rows affected. The ``update()`` method is applied instantly and 1216 the only restriction on the :class:` QuerySet` that is updated is that it can1233 the only restriction on the :class:`.QuerySet` that is updated is that it can 1217 1234 only update columns in the model's main table. Filtering based on related 1218 1235 fields is still possible. You cannot call ``update()`` on a 1219 :class:` QuerySet` that has had a slice taken or can otherwise no longer be1236 :class:`.QuerySet` that has had a slice taken or can otherwise no longer be 1220 1237 filtered. 1221 1238 1222 1239 For example, if you wanted to update all the entries in a particular blog … … 1236 1253 1237 1254 .. method:: delete() 1238 1255 1239 Performs an SQL delete query on all rows in the :class:` QuerySet`. The1256 Performs an SQL delete query on all rows in the :class:`.QuerySet`. The 1240 1257 ``delete()`` is applied instantly. You cannot call ``delete()`` on a 1241 :class:` QuerySet` that has had a slice taken or can otherwise no longer be1258 :class:`.QuerySet` that has had a slice taken or can otherwise no longer be 1242 1259 filtered. 1243 1260 1244 1261 For example, to delete all the entries in a particular blog:: -
docs/topics/http/shortcuts.txt
24 24 25 25 :func:`render()` is the same as a call to 26 26 :func:`render_to_response()` with a `context_instance` argument that 27 that forces the use of a :class:` RequestContext`.27 that forces the use of a :class:`~django.template.RequestContext`. 28 28 29 29 Required arguments 30 30 ------------------ … … 220 220 221 221 .. function:: get_object_or_404(klass, *args, **kwargs) 222 222 223 Calls :meth:`~django.db.models. QuerySet.get()` on a given model manager,223 Calls :meth:`~django.db.models.query.QuerySet.get()` on a given model manager, 224 224 but it raises :class:`~django.http.Http404` instead of the model's 225 225 :class:`~django.core.exceptions.DoesNotExist` exception. 226 226 … … 229 229 230 230 ``klass`` 231 231 A :class:`~django.db.models.Model`, :class:`~django.db.models.Manager` or 232 :class:`~django.db.models.QuerySet` instance from which to get the object. 232 :class:`~django.db.models.query.QuerySet` instance from which to get the 233 object. 233 234 234 235 ``**kwargs`` 235 236 Lookup parameters, which should be in the format accepted by ``get()`` and … … 265 266 266 267 .. function:: get_list_or_404(klass, *args, **kwargs) 267 268 268 Returns the result of :meth:`~django.db.models. QuerySet.filter()` on a269 Returns the result of :meth:`~django.db.models.query.QuerySet.filter()` on a 269 270 given model manager, raising :class:`~django.http.Http404` if the resulting 270 271 list is empty. 271 272