import warnings from collections import OrderedDict from django.apps import apps from django.core import serializers from django.core.management.base import BaseCommand, CommandError from django.core.management.utils import parse_apps_and_model_labels from django.db import DEFAULT_DB_ALIAS, router class ProxyModelWarning(Warning): pass class Command(BaseCommand): help = ( "Output the contents of the database as a fixture of the given format " "(using each model's default manager unless --all is specified)." ) def add_arguments(self, parser): parser.add_argument( 'args', metavar='app_label[.ModelName]', nargs='*', help='Restricts dumped data to the specified app_label or app_label.ModelName.', ) parser.add_argument( '--format', default='json', help='Specifies the output serialization format for fixtures.', ) parser.add_argument( '--indent', type=int, help='Specifies the indent level to use when pretty-printing output.', ) parser.add_argument( '--database', default=DEFAULT_DB_ALIAS, help='Nominates a specific database to dump fixtures from. ' 'Defaults to the "default" database.', ) parser.add_argument( '-e', '--exclude', action='append', default=[], help='An app_label or app_label.ModelName to exclude ' '(use multiple --exclude to exclude multiple apps/models).', ) parser.add_argument( '--natural-foreign', action='store_true', dest='use_natural_foreign_keys', help='Use natural foreign keys if they are available.', ) parser.add_argument( '--natural-primary', action='store_true', dest='use_natural_primary_keys', help='Use natural primary keys if they are available.', ) parser.add_argument( '-a', '--all', action='store_true', dest='use_base_manager', help="Use Django's base manager to dump all models stored in the database, " "including those that would otherwise be filtered or modified by a custom manager.", ) parser.add_argument( '--pks', dest='primary_keys', help="Only dump objects with given primary keys. Accepts a comma-separated " "list of keys. This option only works when you specify one model.", ) parser.add_argument( '-o', '--output', help='Specifies file to which the output is written.' ) def handle(self, *app_labels, **options): format = options['format'] indent = options['indent'] using = options['database'] excludes = options['exclude'] output = options['output'] show_traceback = options['traceback'] use_natural_foreign_keys = options['use_natural_foreign_keys'] use_natural_primary_keys = options['use_natural_primary_keys'] use_base_manager = options['use_base_manager'] pks = options['primary_keys'] if pks: primary_keys = [pk.strip() for pk in pks.split(',')] else: primary_keys = [] excluded_models, excluded_apps = parse_apps_and_model_labels(excludes) if not app_labels: if primary_keys: raise CommandError("You can only use --pks option with one model") app_list = OrderedDict.fromkeys( app_config for app_config in apps.get_app_configs() if app_config.models_module is not None and app_config not in excluded_apps ) else: if len(app_labels) > 1 and primary_keys: raise CommandError("You can only use --pks option with one model") app_list = OrderedDict() for label in app_labels: try: app_label, model_label = label.split('.') try: app_config = apps.get_app_config(app_label) except LookupError as e: raise CommandError(str(e)) if app_config.models_module is None or app_config in excluded_apps: continue try: model = app_config.get_model(model_label) except LookupError: raise CommandError("Unknown model: %s.%s" % (app_label, model_label)) app_list_value = app_list.setdefault(app_config, []) # We may have previously seen a "all-models" request for # this app (no model qualifier was given). In this case # there is no need adding specific models to the list. if app_list_value is not None: if model not in app_list_value: app_list_value.append(model) except ValueError: if primary_keys: raise CommandError("You can only use --pks option with one model") # This is just an app - no model qualifier app_label = label try: app_config = apps.get_app_config(app_label) except LookupError as e: raise CommandError(str(e)) if app_config.models_module is None or app_config in excluded_apps: continue app_list[app_config] = None # Check that the serialization format exists; this is a shortcut to # avoid collating all the objects and _then_ failing. if format not in serializers.get_public_serializer_formats(): try: serializers.get_serializer(format) except serializers.SerializerDoesNotExist: pass raise CommandError("Unknown serialization format: %s" % format) def get_objects(count_only=False): """ Collate the objects to be serialized. If count_only is True, just count the number of objects to be serialized. """ models = serializers.sort_dependencies(app_list.items()) for model in models: if model in excluded_models: continue if model._meta.proxy and model._meta.proxy_for_model not in models: warnings.warn( "%s is a proxy model and won't be serialized." % model._meta.label, category=ProxyModelWarning, ) if not model._meta.proxy and router.allow_migrate_model(using, model): if use_base_manager: objects = model._base_manager else: objects = model._default_manager queryset = objects.using(using).order_by(model._meta.pk.name) if primary_keys: queryset = queryset.filter(pk__in=primary_keys) if count_only: yield queryset.order_by().count() else: yield from queryset.iterator() try: self.stdout.ending = None progress_output = None object_count = 0 # If dumpdata is outputting to stdout, there is no way to display progress if output and self.stdout.isatty() and options['verbosity'] > 0: progress_output = self.stdout object_count = sum(get_objects(count_only=True)) stream = open(output, 'w') if output else None try: serializers.serialize( format, get_objects(), indent=indent, use_natural_foreign_keys=use_natural_foreign_keys, use_natural_primary_keys=use_natural_primary_keys, stream=stream or self.stdout, progress_output=progress_output, object_count=object_count, ) finally: if stream: stream.close() except Exception as e: if show_traceback: raise raise CommandError("Unable to serialize database: %s" % e)