def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def activate(self):
        """
        Syntax sugar that helps at django shell with fast tenant changing

        Usage:
            Tenant.objects.get(schema_name='test').activate()
        """
        connection = connections[get_tenant_database_alias()]
        connection.set_tenant(self)