Commit ed87af32 authored by Alex Hill's avatar Alex Hill Committed by Tim Graham
Browse files

[1.9.x] Fixed #26384 -- Fixed renaming the PK on a model with a self-referential FK on SQLite. 

Backport of 4b2cf1cd from master
parent 026574e0

django/db/backends/sqlite3/schema.py

+9 −1
Original line number Diff line number Diff line
@@ -76,8 +76,16 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): 
          3. copy the data from the old renamed table to the new table

          4. delete the "app_model__old" table

        """

        # Self-referential fields must be recreated rather than copied from

        # the old model to ensure their remote_field.field_name doesn't refer

        # to an altered field.

        def is_self_referential(f):

            return f.is_relation and f.remote_field.model is model

        # Work out the new fields dict / mapping

        body = {f.name: f for f in model._meta.local_concrete_fields}

        body = {

            f.name: f.clone() if is_self_referential(f) else f

            for f in model._meta.local_concrete_fields

        }

        # Since mapping might mix column names and default values,

        # its values must be already quoted.

        mapping = {f.column: self.quote_name(f.column) for f in model._meta.local_concrete_fields}

docs/releases/1.9.5.txt

+3 −0
Original line number Diff line number Diff line
@@ -43,3 +43,6 @@ Bugfixes 


* Fixed a regression with abstract model inheritance and explicit parent links

  (:ticket:`26413`).



* Fixed a migrations crash on SQLite when renaming the primary key of a model

  containing a ``ForeignKey`` to ``'self'`` (:ticket:`26384`).

tests/schema/models.py

+5 −0
Original line number Diff line number Diff line
@@ -177,3 +177,8 @@ class UniqueTest(models.Model): 
    class Meta:

        apps = new_apps

        unique_together = ["year", "slug"]





class Node(models.Model):

    node_id = models.AutoField(primary_key=True)

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

tests/schema/tests.py

+13 −2
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ from .fields import ( 
from .models import (

    Author, AuthorWithDefaultHeight, AuthorWithEvenLongerName, Book,

    BookForeignObj, BookWeak, BookWithLongName, BookWithO2O, BookWithoutAuthor,

    BookWithSlug, IntegerPK, Note, NoteRename, Tag, TagIndexed, TagM2MTest,

    TagUniqueRename, Thing, UniqueTest, new_apps,

    BookWithSlug, IntegerPK, Node, Note, NoteRename, Tag, TagIndexed,

    TagM2MTest, TagUniqueRename, Thing, UniqueTest, new_apps,

)
@@ -1818,3 +1818,14 @@ class SchemaTests(TransactionTestCase): 
            self.get_constraints_for_column(Tag, 'slug'),

            ['schema_tag_slug_2c418ba3_like', 'schema_tag_slug_key']

        )



    def test_alter_pk_with_self_referential_field(self):

        """

        Changing the primary key field name of a model with a self-referential

        foreign key (#26384).

        """

        old_field = Node._meta.get_field('node_id')

        new_field = AutoField(primary_key=True)

        new_field.set_attributes_from_name('id')

        with connection.schema_editor() as editor:

            editor.alter_field(Node, old_field, new_field)