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 unbound_on_Connection(server, user,
                                  password,
                                  auto_bind,
                                  client_strategy,
                                  authentication,
                                  check_names,
                                  auto_referrals, *a, **kwargs):
            return self._on_Connection(server, user,
                                       password,
                                       auto_bind,
                                       client_strategy,
                                       authentication,
                                       check_names,
                                       auto_referrals, *a,
                                       **kwargs)