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mirror of https://github.com/django/django.git synced 2024-12-23 01:25:58 +00:00

Made `pk` a generic expansion for the primary key, rather than just an expansion for __id__exact.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3826 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2006-09-25 13:49:01 +00:00
parent f6ec6d24ab
commit 0c41869e6c
4 changed files with 22 additions and 10 deletions

View File

@ -712,14 +712,10 @@ def parse_lookup(kwarg_items, opts):
# Extract the last elements of the kwarg.
# The very-last is the lookup_type (equals, like, etc).
# The second-last is the table column on which the lookup_type is
# to be performed.
# The exceptions to this are:
# 1) "pk", which is an implicit id__exact;
# if we find "pk", make the lookup_type "exact', and insert
# a dummy name of None, which we will replace when
# we know which table column to grab as the primary key.
# 2) If there is only one part, or the last part is not a query
# term, assume that the query is an __exact
# to be performed. If this name is 'pk', it will be substituted with
# the name of the primary key.
# If there is only one part, or the last part is not a query
# term, assume that the query is an __exact
lookup_type = path.pop()
if lookup_type == 'pk':
lookup_type = 'exact'
@ -766,7 +762,7 @@ def lookup_inner(path, lookup_type, value, opts, table, column):
name = path.pop(0)
# Has the primary key been requested? If so, expand it out
# to be the name of the current class' primary key
if name is None:
if name is None or name == 'pk':
name = current_opts.pk.name
# Try to find the name in the fields associated with the current class

View File

@ -1140,7 +1140,7 @@ The pk lookup shortcut
----------------------
For convenience, Django provides a ``pk`` lookup type, which stands for
"primary_key". This is shorthand for "an exact lookup on the primary-key."
"primary_key".
In the example ``Blog`` model, the primary key is the ``id`` field, so these
three statements are equivalent::
@ -1149,6 +1149,14 @@ three statements are equivalent::
Blog.objects.get(id=14) # __exact is implied
Blog.objects.get(pk=14) # pk implies id__exact
The use of ``pk`` isn't limited to ``__exact`` queries -- any query term
can be combined with ``pk`` to perform a query on the primary key of a model::
# Get blogs entries with id 1, 4 and 7
Blog.objects.filter(pk__in=[1,4,7])
# Get all blog entries with id > 14
Blog.objects.filter(pk__gt=14)
``pk`` lookups also work across joins. For example, these three statements are
equivalent::

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@ -86,6 +86,10 @@ DoesNotExist: Article matching query does not exist.
>>> Article.objects.get(pk=1)
<Article: Area woman programs in Python>
# pk can be used as a shortcut for the primary key name in any query
>>> Article.objects.filter(pk__in=[1])
[<Article: Area woman programs in Python>]
# Model instances of the same type and same ID are considered equal.
>>> a = Article.objects.get(pk=1)
>>> b = Article.objects.get(pk=1)

View File

@ -51,6 +51,10 @@ DoesNotExist: Employee matching query does not exist.
>>> Employee.objects.get(employee_code__exact='ABC123')
<Employee: Dan Jones>
# pk can be used as a substitute for the primary key.
>>> Employee.objects.filter(pk__in=['ABC123','XYZ456'])
[<Employee: Fran Bones>, <Employee: Dan Jones>]
# Fran got married and changed her last name.
>>> fran = Employee.objects.get(pk='XYZ456')
>>> fran.last_name = 'Jones'