def run_migrations_online():
<EOL>def process_revision_directives(context, revision, directives):<EOL><INDENT>if getattr(config.cmd_opts, '<STR_LIT>', False):<EOL><INDENT>script = directives[<NUM_LIT:0>]<EOL>if script.upgrade_ops.is_empty():<EOL><INDENT>directives[:] = []<EOL>logger.info('<STR_LIT>')<EOL><DEDENT><DEDENT><DEDENT>connectable = engine_from_config(<EOL>config.get_section(config.config_ini_section),<EOL>prefix='<STR_LIT>',<EOL>poolclass=pool.NullPool,<EOL>)<EOL>with connectable.connect() as connection:<EOL><INDENT>context.configure(<EOL>connection=connection,<EOL>target_metadata=target_metadata,<EOL>process_revision_directives=process_revision_directives,<EOL>**current_app.extensions['<STR_LIT>'].configure_args<EOL>)<EOL>with context.begin_transaction():<EOL><INDENT>context.run_migrations()<EOL><DEDENT><DEDENT>
Run migrations in 'online' mode.

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