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Code Issues 32 Releases Wiki Activity

[1.7.x] Fixed #22397 -- Issues removing M2M field with explicit through model

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Changed the migration autodetector to remove models last so that FK
and M2M fields will not be left as dangling references. Added a check
in the migration state renderer to error out in the presence of
dangling references instead of leaving them as strings. Fixed a bug
in the sqlite backend to handle the deletion of M2M fields with
"through" models properly (i.e., do nothing successfully).

Thanks to melinath for report, loic for tests and andrewgodwin and
charettes for assistance with architecture.

Backport of 956bd64424 from master
This commit is contained in:
Andrew Gorcester
2014-04-08 12:30:25 +07:00
committed by Simon Charette
parent b06e45bbf6
commit bc5d568e1e
7 changed files with 171 additions and 29 deletions
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59
tests/migrations/test_autodetector.py
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@@ -33,11 +33,15 @@ class AutodetectorTests(TestCase):
other_stable = ModelState("otherapp", "Stable", [("id", models.AutoField(primary_key=True))])
third_thing = ModelState("thirdapp", "Thing", [("id", models.AutoField(primary_key=True))])
book = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("title", models.CharField(max_length=200))])
book_with_no_author = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("title", models.CharField(max_length=200))])
book_with_author_renamed = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Writer")), ("title", models.CharField(max_length=200))])
book_with_field_and_author_renamed = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("writer", models.ForeignKey("testapp.Writer")), ("title", models.CharField(max_length=200))])
book_with_multiple_authors = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("authors", models.ManyToManyField("testapp.Author")), ("title", models.CharField(max_length=200))])
book_with_multiple_authors_through_attribution = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("authors", models.ManyToManyField("testapp.Author", through="otherapp.Attribution")), ("title", models.CharField(max_length=200))])
book_unique = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("title", models.CharField(max_length=200))], {"unique_together": [("author", "title")]})
book_unique_2 = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("title", models.CharField(max_length=200))], {"unique_together": [("title", "author")]})
book_unique_3 = ModelState("otherapp", "Book", [("id", models.AutoField(primary_key=True)), ("newfield", models.IntegerField()), ("author", models.ForeignKey("testapp.Author")), ("title", models.CharField(max_length=200))], {"unique_together": [("title", "newfield")]})
attribution = ModelState("otherapp", "Attribution", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("book", models.ForeignKey("otherapp.Book"))])
edition = ModelState("thirdapp", "Edition", [("id", models.AutoField(primary_key=True)), ("book", models.ForeignKey("otherapp.Book"))])
custom_user = ModelState("thirdapp", "CustomUser", [("id", models.AutoField(primary_key=True)), ("username", models.CharField(max_length=255))])
knight = ModelState("eggs", "Knight", [("id", models.AutoField(primary_key=True))])
@@ -552,7 +556,32 @@ class AutodetectorTests(TestCase):
"""
# Make state
before = self.make_project_state([self.author_with_publisher_string])
after = self.make_project_state([self.author_with_publisher])
after = self.make_project_state([self.author_with_publisher, self.publisher])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertEqual(len(changes['testapp']), 1)
# Right number of actions?
migration = changes['testapp'][0]
self.assertEqual(len(migration.operations), 3)
# Right actions?
action = migration.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
self.assertEqual(action.name, "Publisher")
action = migration.operations[1]
self.assertEqual(action.__class__.__name__, "AddField")
self.assertEqual(action.name, "publisher")
action = migration.operations[2]
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "publisher_name")
def test_foreign_key_removed_before_target_model(self):
"""
Removing an FK and the model it targets in the same change must remove
the FK field before the model to maintain consistency.
"""
before = self.make_project_state([self.author_with_publisher, self.publisher])
after = self.make_project_state([self.author_name]) # removes both the model and FK
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
@@ -560,10 +589,32 @@ class AutodetectorTests(TestCase):
# Right number of actions?
migration = changes['testapp'][0]
self.assertEqual(len(migration.operations), 2)
# Right actions?
# Right actions in right order?
action = migration.operations[0]
self.assertEqual(action.__class__.__name__, "AddField")
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "publisher")
action = migration.operations[1]
self.assertEqual(action.__class__.__name__, "DeleteModel")
self.assertEqual(action.name, "Publisher")
def test_many_to_many_removed_before_through_model(self):
"""
Removing a ManyToManyField and the "through" model in the same change must remove
the field before the model to maintain consistency.
"""
before = self.make_project_state([self.book_with_multiple_authors_through_attribution, self.author_name, self.attribution])
after = self.make_project_state([self.book_with_no_author, self.author_name]) # removes both the through model and ManyToMany
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertEqual(len(changes['otherapp']), 1)
# Right number of actions?
migration = changes['otherapp'][0]
self.assertEqual(len(migration.operations), 2)
# Right actions in right order?
action = migration.operations[0]
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "publisher_name")
self.assertEqual(action.name, "authors")
action = migration.operations[1]
self.assertEqual(action.__class__.__name__, "DeleteModel")
self.assertEqual(action.name, "Attribution")