Commit 283b630d authored by Jean-Louis Fuchs's avatar Jean-Louis Fuchs Committed by Markus Holtermann
Browse files

Fixed #24447 -- Made migrations add FK constraints for existing columns 

When altering from e.g. an IntegerField to a ForeignKey, Django didn't
add a constraint.

Backport of f4f0060f from master
parent 7f2d6099

django/db/backends/schema.py

+3 −3
Original line number Diff line number Diff line
@@ -675,9 +675,9 @@ class BaseDatabaseSchemaEditor(object): 
                }

            )

        # Does it have a foreign key?

        if new_field.rel and \

           (fks_dropped or (old_field.rel and not old_field.db_constraint)) and \

           new_field.db_constraint:

        if (new_field.rel and

                (fks_dropped or not old_field.rel or not old_field.db_constraint) and

                new_field.db_constraint):

            self.execute(self._create_fk_sql(model, new_field, "_fk_%(to_table)s_%(to_column)s"))

        # Rebuild FKs that pointed to us if we previously had to drop them

        if old_field.primary_key and new_field.primary_key and old_type != new_type:

docs/releases/1.7.6.txt

+3 −0
Original line number Diff line number Diff line
@@ -11,3 +11,6 @@ Bugfixes 


* Fixed crash when coercing ``ManyRelatedManager`` to a string

  (:ticket:`24352`).



* Fixed a bug that prevented migrations from adding a FK constraint

  for an existing column. (:ticket:`24447`).

tests/schema/models.py

+9 −0
Original line number Diff line number Diff line
@@ -87,6 +87,15 @@ class BookWithM2M(models.Model): 
        apps = new_apps





class BookWithoutFK(models.Model):

    author = models.IntegerField()

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

    pub_date = models.DateTimeField()



    class Meta:

        apps = new_apps





class TagThrough(models.Model):

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

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

tests/schema/tests.py

+34 −2
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ from .fields import CustomManyToManyField, InheritedManyToManyField 
from .models import (Author, AuthorWithDefaultHeight, AuthorWithM2M, Book, BookWithLongName,

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

    UniqueTest, Thing, TagThrough, BookWithM2MThrough, AuthorTag, AuthorWithM2MThrough,

    AuthorWithEvenLongerName, BookWeak, Note, BookWithO2O)

    AuthorWithEvenLongerName, BookWeak, Note, BookWithO2O, BookWithoutFK)





class SchemaTests(TransactionTestCase):
@@ -29,7 +29,7 @@ class SchemaTests(TransactionTestCase): 
        Author, AuthorWithM2M, Book, BookWithLongName, BookWithSlug,

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

        Thing, TagThrough, BookWithM2MThrough, AuthorWithEvenLongerName,

        BookWeak, BookWithO2O,

        BookWeak, BookWithO2O, BookWithoutFK,

    ]



    # Utility functions
@@ -536,6 +536,38 @@ class SchemaTests(TransactionTestCase): 
        else:

            self.fail("No FK constraint for author_id found")



    @unittest.skipUnless(connection.features.supports_foreign_keys, "No FK support")

    def test_alter_to_fk(self):

        """

        #24447 - Tests adding a FK constraint for an existing column

        """

        # Create the tables

        with connection.schema_editor() as editor:

            editor.create_model(Author)

            editor.create_model(BookWithoutFK)

        # Ensure no FK constraint exists

        constraints = self.get_constraints(BookWithoutFK._meta.db_table)

        for name, details in constraints.items():

            if details['foreign_key']:

                self.fail('Found an unexpected FK constraint to %s' % details['columns'])

        new_field = ForeignKey(Author)

        new_field.set_attributes_from_name("author")

        with connection.schema_editor() as editor:

            editor.alter_field(

                BookWithoutFK,

                BookWithoutFK._meta.get_field_by_name("author")[0],

                new_field,

                strict=True,

            )

        constraints = self.get_constraints(BookWithoutFK._meta.db_table)

        # Ensure FK constraint exists

        for name, details in constraints.items():

            if details['foreign_key'] and details['columns'] == ["author_id"]:

                self.assertEqual(details['foreign_key'], ('schema_author', 'id'))

                break

        else:

            self.fail("No FK constraint for author_id found")



    @unittest.skipUnless(connection.features.supports_foreign_keys, "No FK support")

    def test_alter_o2o_to_fk(self):

        """