def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def _swdb_environment_install(self, env_id, pkg_types, groups):
        swdb_env = self._create_swdb_environment(env_id, pkg_types, groups)

        if swdb_env is not None:
            self._base.history.env.install(swdb_env)