()
Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.
Run migrations in 'online' mode.
Run migrations in online mode .
def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    with get_app().app_context():
        connectable = db.engine

        with connectable.connect() as connection:
            context.configure(
                connection=connection,
                target_metadata=target_metadata,
                compare_type=True
            )

            with context.begin_transaction():
                context.run_migrations()
def run_migrations_online ( ) : with get_app ( ) . app_context ( ) : connectable = db . engine with connectable . connect ( ) as connection : context . configure ( connection = connection , target_metadata = target_metadata , compare_type = True ) with context . begin_transaction ( ) : context . run_migrations ( )