Commit 60c3e55b authored by Luke Plant's avatar Luke Plant
Browse files

Fixed bug with QuerySet.exclude() failing to do negations on Q objects, and 

at the same time generalised exclude/QNot so that they work for 'external'
Q objects i.e. ones that simply have 'get_sql' defined.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@2997 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent c3baf466

django/db/models/query.py

+13 −6
Original line number Diff line number Diff line
@@ -291,22 +291,26 @@ class QuerySet(object): 


    def filter(self, *args, **kwargs):

        "Returns a new QuerySet instance with the args ANDed to the existing set."

        return self._filter_or_exclude(Q, *args, **kwargs)

        return self._filter_or_exclude(None, *args, **kwargs)



    def exclude(self, *args, **kwargs):

        "Returns a new QuerySet instance with NOT (args) ANDed to the existing set."

        return self._filter_or_exclude(QNot, *args, **kwargs)



    def _filter_or_exclude(self, qtype, *args, **kwargs):

    def _filter_or_exclude(self, mapper, *args, **kwargs):

        # mapper is a callable used to transform Q objects,

        # or None for identity transform

        if mapper is None:

            mapper = lambda x: x

        if len(args) > 0 or len(kwargs) > 0:

            assert self._limit is None and self._offset is None, \

                "Cannot filter a query once a slice has been taken."



        clone = self._clone()

        if len(kwargs) > 0:

            clone._filters = clone._filters & qtype(**kwargs)

            clone._filters = clone._filters & mapper(Q(**kwargs))

        if len(args) > 0:

            clone._filters = clone._filters & reduce(operator.and_, args)

            clone._filters = clone._filters & reduce(operator.and_, map(mapper, args))

        return clone



    def complex_filter(self, filter_obj):
@@ -318,7 +322,7 @@ class QuerySet(object): 
        if hasattr(filter_obj, 'get_sql'):

            return self._filter_or_exclude(None, filter_obj)

        else:

            return self._filter_or_exclude(Q, **filter_obj)

            return self._filter_or_exclude(None, **filter_obj)



    def select_related(self, true_or_false=True):

        "Returns a new QuerySet instance with '_select_related' modified."
@@ -582,9 +586,12 @@ class Q(object): 


class QNot(Q):

    "Encapsulates NOT (...) queries as objects"

    def __init__(self, q):

        "Creates a negation of the q object passed in."

        self.q = q



    def get_sql(self, opts):

        tables, joins, where, params = super(QNot, self).get_sql(opts)

        tables, joins, where, params = self.q.get_sql(opts)

        where2 = ['(NOT (%s))' % " AND ".join(where)]

        return tables, joins, where2, params

tests/modeltests/or_lookups/models.py

+4 −0
Original line number Diff line number Diff line
@@ -89,6 +89,10 @@ Hello and goodbye 
>>> Article.objects.filter(Q(headline__startswith='Hello')).in_bulk([1,2])

{1: Hello}



# Demonstrating exclude with a Q object

>>> Article.objects.exclude(Q(headline__startswith='Hello'))

[Goodbye]



# The 'complex_filter' method supports framework features such as 

# 'limit_choices_to' which normally take a single dictionary of lookup arguments

# but need to support arbitrary queries via Q objects too.