Python django.db.migrations.Migration() Examples

def test_sorted_imports(self):
        """
        #24155 - Tests ordering of imports.
        """
        migration = type(str("Migration"), (migrations.Migration,), {
            "operations": [
                migrations.AddField("mymodel", "myfield", models.DateTimeField(
                    default=datetime.datetime(2012, 1, 1, 1, 1, tzinfo=utc),
                )),
            ]
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        self.assertIn(
            "import datetime\n"
            "from django.db import migrations, models\n"
            "from django.utils.timezone import utc\n",
            output
        ) 

def get_fake_model(fields=None, model_base=models.Model, options=None):
    fields = fields if fields else {}
    options = options if options else {}
    """Create fake model to use during unit tests."""

    model = define_fake_model(fields, model_base, options)

    class TestProject:
        def clone(self, *_args, **_kwargs):
            return self

    class TestMigration(migrations.Migration):
        operations = [HStoreExtension()]

    with connection.schema_editor() as schema_editor:
        migration_executor = MigrationExecutor(schema_editor.connection)
        migration_executor.apply_migration(
            TestProject(), TestMigration("caluma_extra", "caluma_core")
        )

        schema_editor.create_model(model)

    return model 

def test_migration_file_header_comments(self):
        """
        Test comments at top of file.
        """
        migration = type("Migration", (migrations.Migration,), {
            "operations": []
        })
        dt = datetime.datetime(2015, 7, 31, 4, 40, 0, 0, tzinfo=utc)
        with mock.patch('django.db.migrations.writer.now', lambda: dt):
            for include_header in (True, False):
                with self.subTest(include_header=include_header):
                    writer = MigrationWriter(migration, include_header)
                    output = writer.as_string()

                    self.assertEqual(
                        include_header,
                        output.startswith(
                            "# Generated by Django %s on 2015-07-31 04:40\n\n" % get_version()
                        )
                    )
                    if not include_header:
                        # Make sure the output starts with something that's not
                        # a comment or indentation or blank line
                        self.assertRegex(output.splitlines(keepends=True)[0], r"^[^#\s]+") 

def test_custom_operation(self):
        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                custom_migration_operations.operations.TestOperation(),
                custom_migration_operations.operations.CreateModel(),
                migrations.CreateModel("MyModel", (), {}, (models.Model,)),
                custom_migration_operations.more_operations.TestOperation()
            ],
            "dependencies": []
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        result = self.safe_exec(output)
        self.assertIn("custom_migration_operations", result)
        self.assertNotEqual(
            result['custom_migration_operations'].operations.TestOperation,
            result['custom_migration_operations'].more_operations.TestOperation
        ) 

def test_sorted_imports(self):
        """
        #24155 - Tests ordering of imports.
        """
        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                migrations.AddField("mymodel", "myfield", models.DateTimeField(
                    default=datetime.datetime(2012, 1, 1, 1, 1, tzinfo=utc),
                )),
            ]
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        self.assertIn(
            "import datetime\n"
            "from django.db import migrations, models\n"
            "from django.utils.timezone import utc\n",
            output
        ) 

def test_custom_operation(self):
        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                custom_migration_operations.operations.TestOperation(),
                custom_migration_operations.operations.CreateModel(),
                migrations.CreateModel("MyModel", (), {}, (models.Model,)),
                custom_migration_operations.more_operations.TestOperation()
            ],
            "dependencies": []
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        result = self.safe_exec(output)
        self.assertIn("custom_migration_operations", result)
        self.assertNotEqual(
            result['custom_migration_operations'].operations.TestOperation,
            result['custom_migration_operations'].more_operations.TestOperation
        ) 

def test_custom_operation(self):
        migration = type(str("Migration"), (migrations.Migration,), {
            "operations": [
                custom_migration_operations.operations.TestOperation(),
                custom_migration_operations.operations.CreateModel(),
                migrations.CreateModel("MyModel", (), {}, (models.Model,)),
                custom_migration_operations.more_operations.TestOperation()
            ],
            "dependencies": []
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        result = self.safe_exec(output)
        self.assertIn("custom_migration_operations", result)
        self.assertNotEqual(
            result['custom_migration_operations'].operations.TestOperation,
            result['custom_migration_operations'].more_operations.TestOperation
        ) 

def get_fake_model(fields=None, model_base=LocalizedModel, meta_options={}):
    """Creates a fake model to use during unit tests."""

    model = define_fake_model(fields, model_base, meta_options)

    class TestProject:
        def clone(self, *_args, **_kwargs):
            return self

        @property
        def apps(self):
            return self

    class TestMigration(migrations.Migration):
        operations = [HStoreExtension()]

    with connection.schema_editor() as schema_editor:
        migration_executor = MigrationExecutor(schema_editor.connection)
        migration_executor.apply_migration(
            TestProject(), TestMigration("eh", "postgres_extra")
        )

        schema_editor.create_model(model)

    return model 

def test_simple_migration(self):
        """
        Tests serializing a simple migration.
        """
        fields = {
            'charfield': models.DateTimeField(default=datetime.datetime.utcnow),
            'datetimefield': models.DateTimeField(default=datetime.datetime.utcnow),
        }

        options = {
            'verbose_name': 'My model',
            'verbose_name_plural': 'My models',
        }

        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                migrations.CreateModel("MyModel", tuple(fields.items()), options, (models.Model,)),
                migrations.CreateModel("MyModel2", tuple(fields.items()), bases=(models.Model,)),
                migrations.CreateModel(
                    name="MyModel3", fields=tuple(fields.items()), options=options, bases=(models.Model,)
                ),
                migrations.DeleteModel("MyModel"),
                migrations.AddField("OtherModel", "datetimefield", fields["datetimefield"]),
            ],
            "dependencies": [("testapp", "some_other_one")],
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        # We don't test the output formatting - that's too fragile.
        # Just make sure it runs for now, and that things look alright.
        result = self.safe_exec(output)
        self.assertIn("Migration", result) 

def test_exclude_migration_tests(self):
        m = Migration("0002_add_new_not_null_field", "app_add_not_null_column")

        linter = MigrationLinter(exclude_migration_tests=[], database="mysql")
        linter.lint_migration(m)
        self.assertTrue(linter.has_errors)

        linter = MigrationLinter(exclude_migration_tests=["NOT_NULL"], database="mysql")
        linter.lint_migration(m)
        self.assertFalse(linter.has_errors) 

def apply_migration(operations, state=None, backwards: bool = False):
    """Executes the specified migration operations using the specified schema
    editor.

    Arguments:
        operations:
            The migration operations to execute.

        state:
            The state state to use during the
            migrations.

        backwards:
            Whether to apply the operations
            in reverse (backwards).
    """

    state = state or migrations.state.ProjectState.from_apps(apps)

    class Migration(migrations.Migration):
        pass

    Migration.operations = operations

    migration = Migration("migration", "tests")
    executor = MigrationExecutor(connection)

    if not backwards:
        executor.apply_migration(state, migration)
    else:
        executor.unapply_migration(state, migration)

    return migration 

def migrate(self, ops, state=None):
        class Migration(migrations.Migration):
            operations = ops
        migration = Migration('name', 'tests')
        inject_trigger_operations([(migration, False)])
        with connection.schema_editor() as schema_editor:
            return migration.apply(state or ProjectState.from_apps(self.apps), schema_editor) 

def test_models_import_omitted(self):
        """
        django.db.models shouldn't be imported if unused.
        """
        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                migrations.AlterModelOptions(
                    name='model',
                    options={'verbose_name': 'model', 'verbose_name_plural': 'models'},
                ),
            ]
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        self.assertIn("from django.db import migrations\n", output) 

def _filter_predicate(target: MigrationTarget, migration: Migration) -> bool:
    # when ``None`` passed as migration name then initial migration from
    # target's app will be chosen and handled properly in ``_get_index``
    # so in final all target app migrations will be excluded from plan
    index = 2 - (target[1] is None)
    return (migration.app_label, migration.name)[:index] == target[:index] 

def backwards(apps, schema_editor):
    """
    Migration nullified after squash of papers
    """
    pass 

def test_migration_path(self):
        test_apps = [
            'migrations.migrations_test_apps.normal',
            'migrations.migrations_test_apps.with_package_model',
            'migrations.migrations_test_apps.without_init_file',
        ]

        base_dir = os.path.dirname(os.path.dirname(__file__))

        for app in test_apps:
            with self.modify_settings(INSTALLED_APPS={'append': app}):
                migration = migrations.Migration('0001_initial', app.split('.')[-1])
                expected_path = os.path.join(base_dir, *(app.split('.') + ['migrations', '0001_initial.py']))
                writer = MigrationWriter(migration)
                self.assertEqual(writer.path, expected_path) 

def test_simple_migration(self):
        """
        Tests serializing a simple migration.
        """
        fields = {
            'charfield': models.DateTimeField(default=datetime.datetime.utcnow),
            'datetimefield': models.DateTimeField(default=datetime.datetime.utcnow),
        }

        options = {
            'verbose_name': 'My model',
            'verbose_name_plural': 'My models',
        }

        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                migrations.CreateModel("MyModel", tuple(fields.items()), options, (models.Model,)),
                migrations.CreateModel("MyModel2", tuple(fields.items()), bases=(models.Model,)),
                migrations.CreateModel(
                    name="MyModel3", fields=tuple(fields.items()), options=options, bases=(models.Model,)
                ),
                migrations.DeleteModel("MyModel"),
                migrations.AddField("OtherModel", "datetimefield", fields["datetimefield"]),
            ],
            "dependencies": [("testapp", "some_other_one")],
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        # We don't test the output formatting - that's too fragile.
        # Just make sure it runs for now, and that things look alright.
        result = self.safe_exec(output)
        self.assertIn("Migration", result) 

def test_models_import_omitted(self):
        """
        django.db.models shouldn't be imported if unused.
        """
        migration = type("Migration", (migrations.Migration,), {
            "operations": [
                migrations.AlterModelOptions(
                    name='model',
                    options={'verbose_name': 'model', 'verbose_name_plural': 'models'},
                ),
            ]
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        self.assertIn("from django.db import migrations\n", output) 

def fix_duplicate_attachments(apps: StateApps, schema_editor: DatabaseSchemaEditor) -> None:
    """Migration 0041 had a bug, where if multiple messages referenced the
    same attachment, rather than creating a single attachment object
    for all of them, we would incorrectly create one for each message.
    This results in exceptions looking up the Attachment object
    corresponding to a file that was used in multiple messages that
    predate migration 0041.

    This migration fixes this by removing the duplicates, moving their
    messages onto a single canonical Attachment object (per path_id).
    """
    Attachment = apps.get_model('zerver', 'Attachment')
    # Loop through all groups of Attachment objects with the same `path_id`
    for group in Attachment.objects.values('path_id').annotate(Count('id')).order_by().filter(id__count__gt=1):
        # Sort by the minimum message ID, to find the first attachment
        attachments = sorted(list(Attachment.objects.filter(path_id=group['path_id']).order_by("id")),
                             key = lambda x: min(x.messages.all().values_list('id')[0]))
        surviving = attachments[0]
        to_cleanup = attachments[1:]
        for a in to_cleanup:
            # For each duplicate attachment, we transfer its messages
            # to the canonical attachment object for that path, and
            # then delete the original attachment.
            for msg in a.messages.all():
                surviving.messages.add(msg)
            surviving.is_realm_public = surviving.is_realm_public or a.is_realm_public
            surviving.save()
            a.delete() 

def migrate_daily_recurrences(apps, schema_editor):
    """
    Migration to convert weekly recurrences into new complex recurrences
    """
    Schedule = apps.get_model("schedules", "Schedule")
    for schedule in Schedule.objects.all():
        schedule.recurrences = recurrence.Recurrence(rrules=[recurrence.Rule(recurrence.WEEKLY, byday=(int(schedule.day), ))])
        schedule.save() 

def test_migration_path(self):
        test_apps = [
            'migrations.migrations_test_apps.normal',
            'migrations.migrations_test_apps.with_package_model',
            'migrations.migrations_test_apps.without_init_file',
        ]

        base_dir = os.path.dirname(os.path.dirname(__file__))

        for app in test_apps:
            with self.modify_settings(INSTALLED_APPS={'append': app}):
                migration = migrations.Migration('0001_initial', app.split('.')[-1])
                expected_path = os.path.join(base_dir, *(app.split('.') + ['migrations', '0001_initial.py']))
                writer = MigrationWriter(migration)
                self.assertEqual(writer.path, expected_path) 

def populate_recipe_type_link_tables(apps, schema_editor):
    # Go through all of the recipe type models and create links for their sub recipes and job types
    JobType = apps.get_model('job', 'JobType')
    RecipeType = apps.get_model('recipe', 'RecipeType')

    total_count = RecipeType.objects.all().count()
    if not total_count:
        return

    print('\nCreating new recipe link table rows: %i' % total_count)
    recipe_types = RecipeType.objects.all()
    done_count = 0
    fail_count = 0
    for rt in recipe_types:
        try:
            create_recipe_type_job_links_from_definition(apps, rt)
            create_recipe_type_sub_links_from_definition(apps, rt)
        except (JobType.DoesNotExist, RecipeType.DoesNotExist) as ex:
            fail_count += 1
            print ('Failed creating links for recipe type %i: %s' % (rt.id, ex))

        done_count += 1
        percent = (float(done_count) / float(total_count)) * 100.00
        print('Progress: %i/%i (%.2f%%)' % (done_count, total_count, percent))

    print ('Migration finished. Failed: %i' % fail_count) 

def copy_prices(apps, schema_editor):
    """
    Validate CoursePrice then iterate over CoursePrice and populate Program.price
    """
    Program = apps.get_model('courses', 'Program')
    CourseRun = apps.get_model('courses', 'CourseRun')

    program_prices = {}
    # Note: we are not filtering on live here because all Programs will require prices and liveness won't matter

    # Validate that there is only one price per program and each run had a price. Else, fail the migration
    for run in CourseRun.objects.all():
        program = run.course.program
        # There must be one and only one price per course run
        try:
            price = run.courseprice_set.get(is_valid=True).price
        except ObjectDoesNotExist as ex:
            raise Exception("Migration failed due to a price missing for run {}".format(
                run.edx_course_key
            )) from ex
        if program.id not in program_prices:
            program_prices[program.id] = price
        elif program_prices[program.id] != price:
            raise Exception("One run in program {program} had price {price1} but another had price {price2}".format(
                program=program,
                price1=program_prices[program.id],
                price2=price,
            ))

    # Verify that all programs have prices at this point (might be false if a Program doesn't have any runs)
    for program in Program.objects.all():
        if program.id not in program_prices:
            raise Exception("Program {} does not have a price (probably due to not having any runs)".format(program))

    # Now, copy the prices
    for program_id, price in program_prices.items():
        program = Program.objects.get(id=program_id)
        program.price = price
        program.save() 

def test_models_import_omitted(self):
        """
        django.db.models shouldn't be imported if unused.
        """
        migration = type(str("Migration"), (migrations.Migration,), {
            "operations": [
                migrations.AlterModelOptions(
                    name='model',
                    options={'verbose_name': 'model', 'verbose_name_plural': 'models'},
                ),
            ]
        })
        writer = MigrationWriter(migration)
        output = writer.as_string()
        self.assertIn("from django.db import migrations\n", output) 

def test_has_errors(self):
        linter = MigrationLinter(database="mysql")
        self.assertFalse(linter.has_errors)

        m = Migration("0001_create_table", "app_add_not_null_column")
        linter.lint_migration(m)
        self.assertFalse(linter.has_errors)

        m = Migration("0002_add_new_not_null_field", "app_add_not_null_column")
        linter.lint_migration(m)
        self.assertTrue(linter.has_errors)

        m = Migration("0001_create_table", "app_add_not_null_column")
        linter.lint_migration(m)
        self.assertTrue(linter.has_errors) 

def rollback_base_playbook_name(apps, schema_editor):
    """
    On rollback, warn that all custom playbook names will be lost.
    The defaults, based on the openedx_release, can be recalculated using the
    function above when the migration is performed.
    """
    print('\nReverting this migration causes data loss...')
    print('All customized playbook_names set will be lost!')


# Migration ################################################################### 

def test_migration_path(self):
        test_apps = [
            'migrations.migrations_test_apps.normal',
            'migrations.migrations_test_apps.with_package_model',
            'migrations.migrations_test_apps.without_init_file',
        ]

        base_dir = os.path.dirname(os.path.dirname(upath(__file__)))

        for app in test_apps:
            with self.modify_settings(INSTALLED_APPS={'append': app}):
                migration = migrations.Migration('0001_initial', app.split('.')[-1])
                expected_path = os.path.join(base_dir, *(app.split('.') + ['migrations', '0001_initial.py']))
                writer = MigrationWriter(migration)
                self.assertEqual(writer.path, expected_path) 

def apply_operations(self, app_label, project_state, operations):
        migration = migrations.Migration("name", app_label)
        migration.operations = operations
        with connection.schema_editor() as editor:
            return migration.apply(project_state, editor) 

def populate_data_type_tags(apps, schema_editor):
    # Go through all of the Ingest models and convert the data_type string into an array of tags
    
    update = 'UPDATE ingest SET data_type_tags = string_to_array(data_type,\',\') WHERE data_type <> \'\''
    with connection.cursor() as cursor:
        cursor.execute(update)
        count = cursor.rowcount
        if count:
            print('%d entries updated with data type tags' % count)

    print ('Migration finished.') 

def populate_data_type_tags(apps, schema_editor):
    # Go through all of the ScaleFile models and convert the data_type string into an array of tags
    update = 'UPDATE scale_file SET data_type_tags = string_to_array(data_type,\',\') WHERE data_type <> \'\''
    with connection.cursor() as cursor:
        cursor.execute(update)
        count = cursor.rowcount
        if count:
            print('%d entries updated with data type tags' % count)

    print ('Migration finished.')