import time from collections import OrderedDict from importlib import import_module from django.apps import apps from django.core.checks import Tags, run_checks from django.core.management.base import ( BaseCommand, CommandError, no_translations, ) from django.core.management.sql import ( emit_post_migrate_signal, emit_pre_migrate_signal, ) from django.db import DEFAULT_DB_ALIAS, connections, router from django.db.migrations.autodetector import MigrationAutodetector from django.db.migrations.executor import MigrationExecutor from django.db.migrations.loader import AmbiguityError from django.db.migrations.state import ModelState, ProjectState from django.utils.module_loading import module_has_submodule from django.utils.text import Truncator class Command(BaseCommand): help = "Updates database schema. Manages both apps with migrations and those without." def add_arguments(self, parser): parser.add_argument( 'app_label', nargs='?', help='App label of an application to synchronize the state.', ) parser.add_argument( 'migration_name', nargs='?', help='Database state will be brought to the state after that ' 'migration. Use the name "zero" to unapply all migrations.', ) parser.add_argument( '--noinput', '--no-input', action='store_false', dest='interactive', help='Tells Django to NOT prompt the user for input of any kind.', ) parser.add_argument( '--database', default=DEFAULT_DB_ALIAS, help='Nominates a database to synchronize. Defaults to the "default" database.', ) parser.add_argument( '--fake', action='store_true', help='Mark migrations as run without actually running them.', ) parser.add_argument( '--fake-initial', action='store_true', help='Detect if tables already exist and fake-apply initial migrations if so. Make sure ' 'that the current database schema matches your initial migration before using this ' 'flag. Django will only check for an existing table name.', ) parser.add_argument( '--plan', action='store_true', help='Shows a list of the migration actions that will be performed.', ) parser.add_argument( '--run-syncdb', action='store_true', help='Creates tables for apps without migrations.', ) def _run_checks(self, **kwargs): issues = run_checks(tags=[Tags.database]) issues.extend(super()._run_checks(**kwargs)) return issues @no_translations def handle(self, *args, **options): self.verbosity = options['verbosity'] self.interactive = options['interactive'] # Import the 'management' module within each installed app, to register # dispatcher events. for app_config in apps.get_app_configs(): if module_has_submodule(app_config.module, "management"): import_module('.management', app_config.name) # Get the database we're operating from db = options['database'] connection = connections[db] # Hook for backends needing any database preparation connection.prepare_database() # Work out which apps have migrations and which do not executor = MigrationExecutor(connection, self.migration_progress_callback) # Raise an error if any migrations are applied before their dependencies. executor.loader.check_consistent_history(connection) # Before anything else, see if there's conflicting apps and drop out # hard if there are any conflicts = executor.loader.detect_conflicts() if conflicts: name_str = "; ".join( "%s in %s" % (", ".join(names), app) for app, names in conflicts.items() ) raise CommandError( "Conflicting migrations detected; multiple leaf nodes in the " "migration graph: (%s).\nTo fix them run " "'python manage.py makemigrations --merge'" % name_str ) # If they supplied command line arguments, work out what they mean. run_syncdb = options['run_syncdb'] target_app_labels_only = True if options['app_label']: # Validate app_label. app_label = options['app_label'] try: apps.get_app_config(app_label) except LookupError as err: raise CommandError(str(err)) if run_syncdb: if app_label in executor.loader.migrated_apps: raise CommandError("Can't use run_syncdb with app '%s' as it has migrations." % app_label) elif app_label not in executor.loader.migrated_apps: raise CommandError("App '%s' does not have migrations." % app_label) if options['app_label'] and options['migration_name']: migration_name = options['migration_name'] if migration_name == "zero": targets = [(app_label, None)] else: try: migration = executor.loader.get_migration_by_prefix(app_label, migration_name) except AmbiguityError: raise CommandError( "More than one migration matches '%s' in app '%s'. " "Please be more specific." % (migration_name, app_label) ) except KeyError: raise CommandError("Cannot find a migration matching '%s' from app '%s'." % ( migration_name, app_label)) targets = [(app_label, migration.name)] target_app_labels_only = False elif options['app_label']: targets = [key for key in executor.loader.graph.leaf_nodes() if key[0] == app_label] else: targets = executor.loader.graph.leaf_nodes() plan = executor.migration_plan(targets) if options['plan']: self.stdout.write('Planned operations:', self.style.MIGRATE_LABEL) if not plan: self.stdout.write(' No planned migration operations.') for migration, backwards in plan: self.stdout.write(str(migration), self.style.MIGRATE_HEADING) for operation in migration.operations: message, is_error = self.describe_operation(operation, backwards) style = self.style.WARNING if is_error else None self.stdout.write(' ' + message, style) return # At this point, ignore run_syncdb if there aren't any apps to sync. run_syncdb = options['run_syncdb'] and executor.loader.unmigrated_apps # Print some useful info if self.verbosity >= 1: self.stdout.write(self.style.MIGRATE_HEADING("Operations to perform:")) if run_syncdb: if options['app_label']: self.stdout.write( self.style.MIGRATE_LABEL(" Synchronize unmigrated app: %s" % app_label) ) else: self.stdout.write( self.style.MIGRATE_LABEL(" Synchronize unmigrated apps: ") + (", ".join(sorted(executor.loader.unmigrated_apps))) ) if target_app_labels_only: self.stdout.write( self.style.MIGRATE_LABEL(" Apply all migrations: ") + (", ".join(sorted({a for a, n in targets})) or "(none)") ) else: if targets[0][1] is None: self.stdout.write(self.style.MIGRATE_LABEL( " Unapply all migrations: ") + "%s" % (targets[0][0],) ) else: self.stdout.write(self.style.MIGRATE_LABEL( " Target specific migration: ") + "%s, from %s" % (targets[0][1], targets[0][0]) ) pre_migrate_state = executor._create_project_state(with_applied_migrations=True) pre_migrate_apps = pre_migrate_state.apps emit_pre_migrate_signal( self.verbosity, self.interactive, connection.alias, apps=pre_migrate_apps, plan=plan, ) # Run the syncdb phase. if run_syncdb: if self.verbosity >= 1: self.stdout.write(self.style.MIGRATE_HEADING("Synchronizing apps without migrations:")) if options['app_label']: self.sync_apps(connection, [app_label]) else: self.sync_apps(connection, executor.loader.unmigrated_apps) # Migrate! if self.verbosity >= 1: self.stdout.write(self.style.MIGRATE_HEADING("Running migrations:")) if not plan: if self.verbosity >= 1: self.stdout.write(" No migrations to apply.") # If there's changes that aren't in migrations yet, tell them how to fix it. autodetector = MigrationAutodetector( executor.loader.project_state(), ProjectState.from_apps(apps), ) changes = autodetector.changes(graph=executor.loader.graph) if changes: self.stdout.write(self.style.NOTICE( " Your models have changes that are not yet reflected " "in a migration, and so won't be applied." )) self.stdout.write(self.style.NOTICE( " Run 'manage.py makemigrations' to make new " "migrations, and then re-run 'manage.py migrate' to " "apply them." )) fake = False fake_initial = False else: fake = options['fake'] fake_initial = options['fake_initial'] post_migrate_state = executor.migrate( targets, plan=plan, state=pre_migrate_state.clone(), fake=fake, fake_initial=fake_initial, ) # post_migrate signals have access to all models. Ensure that all models # are reloaded in case any are delayed. post_migrate_state.clear_delayed_apps_cache() post_migrate_apps = post_migrate_state.apps # Re-render models of real apps to include relationships now that # we've got a final state. This wouldn't be necessary if real apps # models were rendered with relationships in the first place. with post_migrate_apps.bulk_update(): model_keys = [] for model_state in post_migrate_apps.real_models: model_key = model_state.app_label, model_state.name_lower model_keys.append(model_key) post_migrate_apps.unregister_model(*model_key) post_migrate_apps.render_multiple([ ModelState.from_model(apps.get_model(*model)) for model in model_keys ]) # Send the post_migrate signal, so individual apps can do whatever they need # to do at this point. emit_post_migrate_signal( self.verbosity, self.interactive, connection.alias, apps=post_migrate_apps, plan=plan, ) def migration_progress_callback(self, action, migration=None, fake=False): if self.verbosity >= 1: compute_time = self.verbosity > 1 if action == "apply_start": if compute_time: self.start = time.time() self.stdout.write(" Applying %s..." % migration, ending="") self.stdout.flush() elif action == "apply_success": elapsed = " (%.3fs)" % (time.time() - self.start) if compute_time else "" if fake: self.stdout.write(self.style.SUCCESS(" FAKED" + elapsed)) else: self.stdout.write(self.style.SUCCESS(" OK" + elapsed)) elif action == "unapply_start": if compute_time: self.start = time.time() self.stdout.write(" Unapplying %s..." % migration, ending="") self.stdout.flush() elif action == "unapply_success": elapsed = " (%.3fs)" % (time.time() - self.start) if compute_time else "" if fake: self.stdout.write(self.style.SUCCESS(" FAKED" + elapsed)) else: self.stdout.write(self.style.SUCCESS(" OK" + elapsed)) elif action == "render_start": if compute_time: self.start = time.time() self.stdout.write(" Rendering model states...", ending="") self.stdout.flush() elif action == "render_success": elapsed = " (%.3fs)" % (time.time() - self.start) if compute_time else "" self.stdout.write(self.style.SUCCESS(" DONE" + elapsed)) def sync_apps(self, connection, app_labels): """Run the old syncdb-style operation on a list of app_labels.""" with connection.cursor() as cursor: tables = connection.introspection.table_names(cursor) # Build the manifest of apps and models that are to be synchronized. all_models = [ ( app_config.label, router.get_migratable_models(app_config, connection.alias, include_auto_created=False), ) for app_config in apps.get_app_configs() if app_config.models_module is not None and app_config.label in app_labels ] def model_installed(model): opts = model._meta converter = connection.introspection.identifier_converter return not ( (converter(opts.db_table) in tables) or (opts.auto_created and converter(opts.auto_created._meta.db_table) in tables) ) manifest = OrderedDict( (app_name, list(filter(model_installed, model_list))) for app_name, model_list in all_models ) # Create the tables for each model if self.verbosity >= 1: self.stdout.write(" Creating tables...\n") with connection.schema_editor() as editor: for app_name, model_list in manifest.items(): for model in model_list: # Never install unmanaged models, etc. if not model._meta.can_migrate(connection): continue if self.verbosity >= 3: self.stdout.write( " Processing %s.%s model\n" % (app_name, model._meta.object_name) ) if self.verbosity >= 1: self.stdout.write(" Creating table %s\n" % model._meta.db_table) editor.create_model(model) # Deferred SQL is executed when exiting the editor's context. if self.verbosity >= 1: self.stdout.write(" Running deferred SQL...\n") @staticmethod def describe_operation(operation, backwards): """Return a string that describes a migration operation for --plan.""" prefix = '' if hasattr(operation, 'code'): code = operation.reverse_code if backwards else operation.code action = code.__doc__ if code else '' elif hasattr(operation, 'sql'): action = operation.reverse_sql if backwards else operation.sql else: action = '' if backwards: prefix = 'Undo ' if action is None: action = 'IRREVERSIBLE' is_error = True else: action = str(action).replace('\n', '') is_error = False if action: action = ' -> ' + action truncated = Truncator(action) return prefix + operation.describe() + truncated.chars(40), is_error