错误：【Self referencing loop detected with type】

Newtonsoft环境：LINQ+Newtonsoft

问题：若两表间有外键，如图

如果代码按如下写法则会报错：【Self referencing loop detected with type】

        var result = db.T_ZiGeJingLi.Where(p => p.ID == Convert.ToInt32(ZGZSID));
        string json = JsonConvert.SerializeObject(result);

经如下修改语句则会正常：

        var result = from i in db.T_ZiGeJingLi
                     where i.ID == Convert.ToInt32(ZGZSID)
                     select new
                     {
                         ID = i.ID,
                         ZhengShuBianHao = i.ZhengShuBianHao,
                         ZhengShuMingCheng = i.ZhengShuMingCheng,
                         HuoZhengDate = i.HuoZhengDate,
                         FaZhengJiGou = i.FaZhengJiGou,
                         Memo = i.Memo,
                         EmpID = i.EmpID
                     };
        string json = JsonConvert.SerializeObject(result);

错误：【Self referencing loop detected with type】

原文：http://blog.csdn.net/jin8907/article/details/48028505