Commit 6b078044 authored by Andrew Godwin's avatar Andrew Godwin
Browse files

Fixed #22183: Through M2Ms now correctly handled

parent cdf6eba1

django/db/backends/schema.py

+2 −1
Original line number Diff line number Diff line
@@ -262,6 +262,7 @@ class BaseDatabaseSchemaEditor(object): 
            })

        # Make M2M tables

        for field in model._meta.local_many_to_many:

            if field.rel.through._meta.auto_created:

                self.create_model(field.rel.through)



    def delete_model(self, model):

django/db/models/fields/related.py

+5 −0
Original line number Diff line number Diff line
@@ -2032,6 +2032,11 @@ class ManyToManyField(RelatedField): 
            kwargs['to'] = self.rel.to

        else:

            kwargs['to'] = "%s.%s" % (self.rel.to._meta.app_label, self.rel.to._meta.object_name)

        if getattr(self.rel, 'through', None) is not None:

            if isinstance(self.rel.through, six.string_types):

                kwargs['through'] = self.rel.through

            else:

                kwargs['through'] = "%s.%s" % (self.rel.through._meta.app_label, self.rel.through._meta.object_name)

        # If swappable is True, then see if we're actually pointing to the target

        # of a swap.

        swappable_setting = self.swappable_setting

tests/field_deconstruction/tests.py

+6 −0
Original line number Diff line number Diff line
@@ -242,6 +242,12 @@ class FieldDeconstructionTests(TestCase): 
        self.assertEqual(args, [])

        self.assertEqual(kwargs, {"to": "auth.User"})

        self.assertEqual(kwargs['to'].setting_name, "AUTH_USER_MODEL")

        # Test through

        field = models.ManyToManyField("auth.Permission", through="auth.Group")

        name, path, args, kwargs = field.deconstruct()

        self.assertEqual(path, "django.db.models.ManyToManyField")

        self.assertEqual(args, [])

        self.assertEqual(kwargs, {"to": "auth.Permission", "through": "auth.Group"})



    @override_settings(AUTH_USER_MODEL="auth.Permission")

    def test_many_to_many_field_swapped(self):

tests/schema/models.py

+15 −0
Original line number Diff line number Diff line
@@ -44,6 +44,21 @@ class BookWithM2M(models.Model): 
        apps = new_apps





class TagThrough(models.Model):

    book = models.ForeignKey("schema.BookWithM2MThrough")

    tag = models.ForeignKey("schema.TagM2MTest")



    class Meta:

        apps = new_apps





class BookWithM2MThrough(models.Model):

    tags = models.ManyToManyField("TagM2MTest", related_name="books", through=TagThrough)



    class Meta:

        apps = new_apps





class BookWithSlug(models.Model):

    author = models.ForeignKey(Author)

    title = models.CharField(max_length=100, db_index=True)

tests/schema/tests.py

+16 −2
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ from django.db.models.fields.related import ManyToManyField, ForeignKey 
from django.db.transaction import atomic

from .models import (Author, AuthorWithM2M, Book, BookWithLongName,

    BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename,

    UniqueTest, Thing)

    UniqueTest, Thing, TagThrough, BookWithM2MThrough)





class SchemaTests(TransactionTestCase):
@@ -26,7 +26,7 @@ class SchemaTests(TransactionTestCase): 
    models = [

        Author, AuthorWithM2M, Book, BookWithLongName, BookWithSlug,

        BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename, UniqueTest,

        Thing

        Thing, TagThrough, BookWithM2MThrough

    ]



    # Utility functions
@@ -310,6 +310,20 @@ class SchemaTests(TransactionTestCase): 
        columns = self.column_classes(BookWithM2M._meta.get_field_by_name("tags")[0].rel.through)

        self.assertEqual(columns['tagm2mtest_id'][0], "IntegerField")



    def test_m2m_create_through(self):

        """

        Tests M2M fields on models during creation with through models

        """

        # Create the tables

        with connection.schema_editor() as editor:

            editor.create_model(TagThrough)

            editor.create_model(TagM2MTest)

            editor.create_model(BookWithM2MThrough)

        # Ensure there is now an m2m table there

        columns = self.column_classes(TagThrough)

        self.assertEqual(columns['book_id'][0], "IntegerField")

        self.assertEqual(columns['tag_id'][0], "IntegerField")



    def test_m2m(self):

        """

        Tests adding/removing M2M fields on models