个人常用：

            where=msg_id
            sql='''
                select t.id, t.real_name, t2.* from auth_user t join (
                    select max(is_red) as is_red,add_user_id,task_id from card where msg_id=%s GROUP BY task_id,add_user_id)
                t2 ON t2.add_user_id=t.id
                ''' %where
            cursor = connection.cursor()
            cursor.execute(sql)
            fetchall = cursor.fetchall()
 
            card=[]
            for obj in fetchall:
                dic={}
                dic['user_id']=obj[0]
                dic['real_name']=obj[1]
                dic['is_red']=obj[2]
                dic['add_user']=obj[3]
                dic['task_id']=obj[4]
                card.append(dic)
            context['card']=card

节选自：https://blog.csdn.net/u012422446/article/details/52623069