has_missing_migrations.py 文件源码

def handle(self, *args, **options):
        changed = set()

        self.stdout.write("Checking...")
        for db in settings.DATABASES.keys():
            try:
                executor = MigrationExecutor(connections[db])
            except OperationalError:
                sys.exit("Unable to check migrations: cannot connect to database\n")

            autodetector = MigrationAutodetector(
                executor.loader.project_state(),
                ProjectState.from_apps(apps),
            )
            changed.update(autodetector.changes(graph=executor.loader.graph).keys())

        changed -= set(options['ignore'])

        if changed:
            sys.exit(
                "Apps with model changes but no corresponding migration file: %(changed)s\n" % {
                    'changed': list(changed)
                })
        else:
            sys.stdout.write("All migration files present\n")