[1.7.x] Fixed #23938 -- Added migration support for m2m to concrete fields and vice versa

Thanks to Michael D. Hoyle for the report and Tim Graham for the review.

Backport of 623ccdd598 from master
This commit is contained in:
Markus Holtermann 2014-12-02 19:25:46 +01:00 committed by Tim Graham
parent 1cbdb49b0a
commit 1702bc52cc
3 changed files with 123 additions and 80 deletions

View File

@ -778,73 +778,71 @@ class MigrationAutodetector(object):
Fields that have been added
"""
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
field = self.new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0]
# Fields that are foreignkeys/m2ms depend on stuff
dependencies = []
if field.rel and field.rel.to:
# Account for FKs to swappable models
swappable_setting = getattr(field, 'swappable_setting', None)
if swappable_setting is not None:
dep_app_label = "__setting__"
dep_object_name = swappable_setting
else:
dep_app_label = field.rel.to._meta.app_label
dep_object_name = field.rel.to._meta.object_name
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.rel, "through", None) and not field.rel.through._meta.auto_created:
dependencies.append((
field.rel.through._meta.app_label,
field.rel.through._meta.object_name,
None,
True
))
# You can't just add NOT NULL fields with no default or fields
# which don't allow empty strings as default.
if (not field.null and not field.has_default() and
not isinstance(field, models.ManyToManyField) and
not (field.blank and field.empty_strings_allowed)):
field = field.clone()
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=False,
),
dependencies=dependencies,
)
self._generate_added_field(app_label, model_name, field_name)
def _generate_added_field(self, app_label, model_name, field_name):
field = self.new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0]
# Fields that are foreignkeys/m2ms depend on stuff
dependencies = []
if field.rel and field.rel.to:
# Account for FKs to swappable models
swappable_setting = getattr(field, 'swappable_setting', None)
if swappable_setting is not None:
dep_app_label = "__setting__"
dep_object_name = swappable_setting
else:
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
),
dependencies=dependencies,
)
dep_app_label = field.rel.to._meta.app_label
dep_object_name = field.rel.to._meta.object_name
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.rel, "through", None) and not field.rel.through._meta.auto_created:
dependencies.append((
field.rel.through._meta.app_label,
field.rel.through._meta.object_name,
None,
True,
))
# You can't just add NOT NULL fields with no default or fields
# which don't allow empty strings as default.
preserve_default = True
if (not field.null and not field.has_default() and
not isinstance(field, models.ManyToManyField) and
not (field.blank and field.empty_strings_allowed)):
field = field.clone()
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
preserve_default = False
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
def generate_removed_fields(self):
"""
Fields that have been removed.
"""
for app_label, model_name, field_name in sorted(self.old_field_keys - self.new_field_keys):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
),
# We might need to depend on the removal of an
# order_with_respect_to or index/unique_together operation;
# this is safely ignored if there isn't one
dependencies=[
(app_label, model_name, field_name, "order_wrt_unset"),
(app_label, model_name, field_name, "foo_together_change"),
],
)
self._generate_removed_field(app_label, model_name, field_name)
def _generate_removed_field(self, app_label, model_name, field_name):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
),
# We might need to depend on the removal of an
# order_with_respect_to or index/unique_together operation;
# this is safely ignored if there isn't one
dependencies=[
(app_label, model_name, field_name, "order_wrt_unset"),
(app_label, model_name, field_name, "foo_together_change"),
],
)
def generate_altered_fields(self):
"""
@ -868,25 +866,30 @@ class MigrationAutodetector(object):
old_field_dec = self.deep_deconstruct(old_field)
new_field_dec = self.deep_deconstruct(new_field)
if old_field_dec != new_field_dec:
preserve_default = True
if (old_field.null and not new_field.null and not new_field.has_default() and
if (not isinstance(old_field, models.ManyToManyField) and
not isinstance(new_field, models.ManyToManyField)):
field = new_field.clone()
new_default = self.questioner.ask_not_null_alteration(field_name, model_name)
if new_default is not models.NOT_PROVIDED:
field.default = new_default
preserve_default = False
else:
field = new_field
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
preserve_default = True
if (old_field.null and not new_field.null and not new_field.has_default() and
not isinstance(new_field, models.ManyToManyField)):
field = new_field.clone()
new_default = self.questioner.ask_not_null_alteration(field_name, model_name)
if new_default is not models.NOT_PROVIDED:
field.default = new_default
preserve_default = False
else:
field = new_field
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
)
)
)
else:
self._generate_removed_field(app_label, model_name, field_name)
self._generate_added_field(app_label, model_name, field_name)
def _generate_altered_foo_together(self, operation):
option_name = operation.option_name

View File

@ -44,7 +44,7 @@ Bugfixes
* Fixed a migration crash that prevented changing a nullable field with a
default to non-nullable with the same default (:ticket:`23738`).
* Fixed a migrations crash when adding ``GeometryField``\s with ``blank=True``
* Fixed a migration crash when adding ``GeometryField``\s with ``blank=True``
on PostGIS (:ticket:`23731`).
* Allowed usage of ``DateTimeField()`` as ``Transform.output_field``
@ -63,7 +63,7 @@ Bugfixes
* Fixed a migration crash when a field is renamed that is part of an
``index_together`` (:ticket:`23859`).
* Fixed :djadmin:`squashmigrations` to respect the ``--no-optimize`` parameter
* Fixed :djadmin:`squashmigrations` to respect the ``--no-optimize`` parameter
(:ticket:`23799`).
* Made :class:`~django.db.migrations.operations.RenameModel` reversible
@ -144,7 +144,7 @@ Bugfixes
* ``makemigrations`` no longer prompts for a default value when adding
``TextField()`` or ``CharField()`` without a ``default`` (:ticket:`23405`).
* Fixed migration crash when adding ``order_with_respect_to`` to a table
* Fixed a migration crash when adding ``order_with_respect_to`` to a table
with existing rows (:ticket:`23983`).
* Restored the ``pre_migrate`` signal if all apps have migrations
@ -181,3 +181,6 @@ Bugfixes
* Supported strings escaped by third-party libraries with the ``__html__``
convention in the template engine (:ticket:`23831`).
* Fixed a migration crash when changing a ``ManyToManyField`` into a concrete
field and vice versa (:ticket:`23938`).

View File

@ -116,6 +116,10 @@ class AutodetectorTests(TestCase):
("id", models.AutoField(primary_key=True)),
("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Contract")),
])
author_with_former_m2m = ModelState("testapp", "Author", [
("id", models.AutoField(primary_key=True)),
("publishers", models.CharField(max_length=100)),
])
author_with_options = ModelState("testapp", "Author", [
("id", models.AutoField(primary_key=True)),
], {
@ -1274,6 +1278,39 @@ class AutodetectorTests(TestCase):
self.assertOperationAttributes(changes, "testapp", 0, 3, name="publisher", model_name='contract')
self.assertOperationAttributes(changes, "testapp", 0, 4, name="Contract")
def test_concrete_field_changed_to_many_to_many(self):
"""
#23938 - Tests that changing a concrete field into a ManyToManyField
first removes the concrete field and then adds the m2m field.
"""
before = self.make_project_state([self.author_with_former_m2m])
after = self.make_project_state([self.author_with_m2m, self.publisher])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number/type of migrations?
self.assertNumberMigrations(changes, "testapp", 1)
self.assertOperationTypes(changes, "testapp", 0, ["CreateModel", "RemoveField", "AddField"])
self.assertOperationAttributes(changes, 'testapp', 0, 0, name='Publisher')
self.assertOperationAttributes(changes, 'testapp', 0, 1, name="publishers", model_name='author')
self.assertOperationAttributes(changes, 'testapp', 0, 2, name="publishers", model_name='author')
def test_many_to_many_changed_to_concrete_field(self):
"""
#23938 - Tests that changing a ManyToManyField into a concrete field
first removes the m2m field and then adds the concrete field.
"""
before = self.make_project_state([self.author_with_m2m, self.publisher])
after = self.make_project_state([self.author_with_former_m2m])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number/type of migrations?
self.assertNumberMigrations(changes, "testapp", 1)
self.assertOperationTypes(changes, "testapp", 0, ["RemoveField", "AddField", "DeleteModel"])
self.assertOperationAttributes(changes, 'testapp', 0, 0, name="publishers", model_name='author')
self.assertOperationAttributes(changes, 'testapp', 0, 1, name="publishers", model_name='author')
self.assertOperationAttributes(changes, 'testapp', 0, 2, name='Publisher')
self.assertOperationFieldAttributes(changes, 'testapp', 0, 1, max_length=100)
def test_non_circular_foreignkey_dependency_removal(self):
"""
If two models with a ForeignKey from one to the other are removed at the