def robotsrulesetOfDomain(self, domain):
		'''检查domain是否在数据库中,
			否 --> (False, None)
			是 --> (True, 数据库中存储的robots.txt内容)
		'''
		exist = False
		cur = self.conn.cursor()
		# 是否存在
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		if cur.fetchone() :
			exist = True
		# 存在的话,结果是什么
		cur.execute("SELECT rules FROM Domains,Rulesets "
			"WHERE domain=? AND Domains.did=Rulesets.did"
			,(domain,) )
		ruleset = cur.fetchone()
		return (exist, ruleset)
def from_json(self, filename: str, silent: bool = False) -> bool:
        """Update the values in the config from a JSON file. The loaded
        data is passed to the :meth:`from_mapping` method.

        :param filename: The path to the JSON file. This can be an
            absolute path or relative to the config root path.
        :param silent: Ignore the file if it doesn't exist.

        .. deprecated:: 2.0.0
            Will be removed in Flask 2.1. Use :meth:`from_file` instead.
            This was removed early in 2.0.0, was added back in 2.0.1.

        .. versionadded:: 0.11
        """
        import warnings
        from . import json

        warnings.warn(
            "'from_json' is deprecated and will be removed in Flask"
            " 2.1. Use 'from_file(path, json.load)' instead.",
            DeprecationWarning,
            stacklevel=2,
        )
        return self.from_file(filename, json.load, silent=silent)