sqlmigrate doesn t support coloring its output but we need to force nocolortrue so that the begincommit statements added by outputtransaction don t get colored either get the database we re operating from load up a loader to get all the migration data but don t replace migrations resolve commandline arguments into a migration validate applabel show beginend around output for atomic migrations if the database supports transactional ddl make a plan that represents just the requested migrations and show sql for it sqlmigrate doesn t support coloring its output but we need to force no_color true so that the begin commit statements added by output_transaction don t get colored either get the database we re operating from load up a loader to get all the migration data but don t replace migrations resolve command line arguments into a migration validate app_label show begin end around output for atomic migrations if the database supports transactional ddl make a plan that represents just the requested migrations and show sql for it
from django.apps import apps
from django.core.management.base import BaseCommand, CommandError
from django.db import DEFAULT_DB_ALIAS, connections
from django.db.migrations.loader import AmbiguityError, MigrationLoader


class Command(BaseCommand):
    help = "Prints the SQL statements for the named migration."

    output_transaction = True

    def add_arguments(self, parser):
        parser.add_argument(
            "app_label", help="App label of the application containing the migration."
        )
        parser.add_argument(
            "migration_name", help="Migration name to print the SQL for."
        )
        parser.add_argument(
            "--database",
            default=DEFAULT_DB_ALIAS,
            help=(
                'Nominates a database to create SQL for. Defaults to the "default" '
                "database."
            ),
        )
        parser.add_argument(
            "--backwards",
            action="store_true",
            help="Creates SQL to unapply the migration, rather than to apply it",
        )

    def execute(self, *args, **options):
        
        
        
        options["no_color"] = True
        return super().execute(*args, **options)

    def handle(self, *args, **options):
        
        connection = connections[options["database"]]

        
        
        loader = MigrationLoader(connection, replace_migrations=False)

        
        app_label, migration_name = options["app_label"], options["migration_name"]
        
        try:
            apps.get_app_config(app_label)
        except LookupError as err:
            raise CommandError(str(err))
        if app_label not in loader.migrated_apps:
            raise CommandError("App '%s' does not have migrations" % app_label)
        try:
            migration = 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'. Is it in "
                "INSTALLED_APPS?" % (migration_name, app_label)
            )
        target = (app_label, migration.name)

        
        
        self.output_transaction = (
            migration.atomic and connection.features.can_rollback_ddl
        )

        
        
        plan = [(loader.graph.nodes[target], options["backwards"])]
        sql_statements = loader.collect_sql(plan)
        if not sql_statements and options["verbosity"] >= 1:
            self.stderr.write("No operations found.")
        return "\n".join(sql_statements)