Commit fd46f673 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

Fixed #9926 -- Fixes for some select_related() situations. 

Using select_related(...) across a nullable relation to a multi-table
model inheritance situation no longer excludes results. Thanks to AdamG
for a test demonstrating part of the problem.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10136 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent c5aa6fa7

django/db/models/sql/query.py

+11 −3
Original line number Diff line number Diff line
@@ -770,6 +770,7 @@ class BaseQuery(object): 
                continue

            if as_pairs:

                result.append((alias, field.column))

                aliases.add(alias)

                continue

            if with_aliases and field.column in col_aliases:

                c_alias = 'Col%d' % len(col_aliases)
@@ -784,7 +785,7 @@ class BaseQuery(object): 
                if with_aliases:

                    col_aliases.add(field.column)

        if as_pairs:

            return result, None

            return result, aliases

        return result, aliases



    def get_from_clause(self):
@@ -1342,6 +1343,7 @@ class BaseQuery(object): 
            if model:

                int_opts = opts

                alias = root_alias

                alias_chain = []

                for int_model in opts.get_base_chain(model):

                    lhs_col = int_opts.parents[int_model].column

                    dedupe = lhs_col in opts.duplicate_targets
@@ -1353,8 +1355,11 @@ class BaseQuery(object): 
                    alias = self.join((alias, int_opts.db_table, lhs_col,

                            int_opts.pk.column), exclusions=used,

                            promote=promote)

                    alias_chain.append(alias)

                    for (dupe_opts, dupe_col) in dupe_set:

                        self.update_dupe_avoidance(dupe_opts, dupe_col, alias)

                if self.alias_map[root_alias][JOIN_TYPE] == self.LOUTER:

                    self.promote_alias_chain(alias_chain, True)

            else:

                alias = root_alias
@@ -1368,8 +1373,11 @@ class BaseQuery(object): 
                    f.rel.get_related_field().column),

                    exclusions=used.union(avoid), promote=promote)

            used.add(alias)

            self.related_select_cols.extend(self.get_default_columns(

                start_alias=alias, opts=f.rel.to._meta, as_pairs=True)[0])

            columns, aliases = self.get_default_columns(start_alias=alias,

                    opts=f.rel.to._meta, as_pairs=True)

            self.related_select_cols.extend(columns)

            if self.alias_map[alias][JOIN_TYPE] == self.LOUTER:

                self.promote_alias_chain(aliases, True)

            self.related_select_fields.extend(f.rel.to._meta.fields)

            if restricted:

                next = requested.get(f.name, {})

tests/regressiontests/queries/models.py

+16 −2
Original line number Diff line number Diff line
@@ -16,10 +16,17 @@ try: 
except NameError:

    from django.utils.itercompat import sorted



class DumbCategory(models.Model):

    pass



class NamedCategory(DumbCategory):

    name = models.CharField(max_length=10)



class Tag(models.Model):

    name = models.CharField(max_length=10)

    parent = models.ForeignKey('self', blank=True, null=True,

            related_name='children')

    category = models.ForeignKey(NamedCategory, null=True, default=None)



    class Meta:

        ordering = ['name']
@@ -266,8 +273,9 @@ class Plaything(models.Model): 




__test__ = {'API_TESTS':"""

>>> t1 = Tag.objects.create(name='t1')

>>> t2 = Tag.objects.create(name='t2', parent=t1)

>>> generic = NamedCategory.objects.create(name="Generic")

>>> t1 = Tag.objects.create(name='t1', category=generic)

>>> t2 = Tag.objects.create(name='t2', parent=t1, category=generic)

>>> t3 = Tag.objects.create(name='t3', parent=t1)

>>> t4 = Tag.objects.create(name='t4', parent=t3)

>>> t5 = Tag.objects.create(name='t5', parent=t3)
@@ -726,6 +734,12 @@ Bug #6981 
>>> Tag.objects.select_related('parent').order_by('name')

[<Tag: t1>, <Tag: t2>, <Tag: t3>, <Tag: t4>, <Tag: t5>]



Bug #9926

>>> Tag.objects.select_related("parent", "category").order_by('name')

[<Tag: t1>, <Tag: t2>, <Tag: t3>, <Tag: t4>, <Tag: t5>]

>>> Tag.objects.select_related('parent', "parent__category").order_by('name')

[<Tag: t1>, <Tag: t2>, <Tag: t3>, <Tag: t4>, <Tag: t5>]



Bug #6180, #6203 -- dates with limits and/or counts

>>> Item.objects.count()

4

tests/regressiontests/select_related_regress/models.py

+25 −0
Original line number Diff line number Diff line
@@ -65,6 +65,23 @@ class Client(models.Model): 
    state = models.ForeignKey(State, null=True)

    status = models.ForeignKey(ClientStatus)



# Some model inheritance exercises

class Parent(models.Model):

    name = models.CharField(max_length=10)



    def __unicode__(self):

        return self.name



class Child(Parent):

    value = models.IntegerField()



class Item(models.Model):

    name = models.CharField(max_length=10)

    child = models.ForeignKey(Child, null=True)



    def __unicode__(self):

        return self.name



__test__ = {'API_TESTS': """

Regression test for bug #7110. When using select_related(), we must query the

Device and Building tables using two different aliases (each) in order to
@@ -140,4 +157,12 @@ for country before getting status. 
<ClientStatus: ClientStatus object>

>>> Client.objects.select_related('status')[0].status

<ClientStatus: ClientStatus object>



Exercising select_related() with multi-table model inheritance.

>>> c1 = Child.objects.create(name="child1", value=42)

>>> _ = Item.objects.create(name="item1", child=c1)

>>> _ = Item.objects.create(name="item2")

>>> Item.objects.select_related("child").order_by("name")

[<Item: item1>, <Item: item2>]



"""}