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.
This commit is contained in:
Markus Holtermann 2014-12-02 19:25:46 +01:00 committed by Tim Graham
parent 3c5d1edb39
commit 623ccdd598
3 changed files with 123 additions and 80 deletions

View File

@ -773,73 +773,71 @@ 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):
"""
@ -863,25 +861,30 @@ 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

@ -126,6 +126,10 @@ 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)),
], {
@ -1326,6 +1330,39 @@ class AutodetectorTests(TestCase):
self.assertOperationAttributes(changes, "testapp", 0, 3, name="Author")
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