Don't make a second migration if there was a force-null-default addcol. (ce05b8a6) · Commits · Dom Sekotill / django

django/db/migrations/autodetector.py

+20 −8

Original line number	Diff line number	Diff line
		@@ -188,7 +188,18 @@ class MigrationAutodetector(object):
		continue
		# You can't just add NOT NULL fields with no default
		if not field.null and not field.has_default():
		field = field.clone()
		field.default = self.questioner.ask_not_null_addition(field_name, model_name)
		self.add_to_migration(
		app_label,
		operations.AddField(
		model_name=model_name,
		name=field_name,
		field=field,
		preserve_default=False,
		)
		)
		else:
		self.add_to_migration(
		app_label,
		operations.AddField(
		@@ -434,7 +445,8 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
		"Adding a NOT NULL field to a model"
		choice = self._choice_input(
		"You are trying to add a non-nullable field '%s' to %s without a default;\n" % (field_name, model_name) +
		"this is not possible. Please select a fix:",
		"we can't do that (the database needs something to populate existing rows).\n" +
		"Please select a fix:",
		[
		"Provide a one-off default now (will be set on all existing rows)",
		"Quit, and let me add a default in models.py",

django/db/migrations/operations/fields.py

+10 −2

Original line number	Diff line number	Diff line
		from django.db import router
		from django.db.models.fields import NOT_PROVIDED
		from .base import Operation


		@@ -7,13 +8,20 @@ class AddField(Operation):
		Adds a field to a model.
		"""

		def __init__(self, model_name, name, field):
		def __init__(self, model_name, name, field, preserve_default=True):
		self.model_name = model_name
		self.name = name
		self.field = field
		self.preserve_default = preserve_default

		def state_forwards(self, app_label, state):
		state.models[app_label, self.model_name.lower()].fields.append((self.name, self.field))
		# If preserve default is off, don't use the default for future state
		if not self.preserve_default:
		field = self.field.clone()
		field.default = NOT_PROVIDED
		else:
		field = self.field
		state.models[app_label, self.model_name.lower()].fields.append((self.name, field))

		def database_forwards(self, app_label, schema_editor, from_state, to_state):
		from_model = from_state.render().get_model(app_label, self.model_name)

tests/migrations/test_operations.py

+33 −1

Original line number	Diff line number	Diff line
		from django.db import connection, models, migrations, router
		from django.db.models.fields import NOT_PROVIDED
		from django.db.transaction import atomic
		from django.db.utils import IntegrityError
		from django.db.migrations.state import ProjectState
		@@ -130,10 +131,19 @@ class OperationTests(MigrationTestBase):
		"""
		project_state = self.set_up_test_model("test_adfl")
		# Test the state alteration
		operation = migrations.AddField("Pony", "height", models.FloatField(null=True))
		operation = migrations.AddField(
		"Pony",
		"height",
		models.FloatField(null=True, default=5),
		)
		new_state = project_state.clone()
		operation.state_forwards("test_adfl", new_state)
		self.assertEqual(len(new_state.models["test_adfl", "pony"].fields), 4)
		field = [
		f for n, f in new_state.models["test_adfl", "pony"].fields
		if n == "height"
		][0]
		self.assertEqual(field.default, 5)
		# Test the database alteration
		self.assertColumnNotExists("test_adfl_pony", "height")
		with connection.schema_editor() as editor:
		@@ -144,6 +154,28 @@ class OperationTests(MigrationTestBase):
		operation.database_backwards("test_adfl", editor, new_state, project_state)
		self.assertColumnNotExists("test_adfl_pony", "height")

		def test_add_field_preserve_default(self):
		"""
		Tests the AddField operation's state alteration
		when preserve_default = False.
		"""
		project_state = self.set_up_test_model("test_adflpd")
		# Test the state alteration
		operation = migrations.AddField(
		"Pony",
		"height",
		models.FloatField(null=True, default=4),
		preserve_default = False,
		)
		new_state = project_state.clone()
		operation.state_forwards("test_adflpd", new_state)
		self.assertEqual(len(new_state.models["test_adflpd", "pony"].fields), 4)
		field = [
		f for n, f in new_state.models["test_adflpd", "pony"].fields
		if n == "height"
		][0]
		self.assertEqual(field.default, NOT_PROVIDED)

		def test_add_field_m2m(self):
		"""
		Tests the AddField operation with a ManyToManyField.