Linq to Entities-在where子句中Havine a Guid会抛出错误

Question

这是我的代码

var bms = from b in context.bookmark
                     join q in context.question1Set on b.bookmark_id equals q.question_id
                     join u in context.userinfo on b.bookmark_ownerid equals u.user_userid
                     where b.bookmark_ownerid == new Guid(userid.ToString()) && q.question_isdeleted == false //i think it dosent't like the new Guid
                     select new
                     {
                         u.user_username,
                         q.question_title
                     };

        foreach (var bm in bms)
        {
            question q = new question();
            q.Username = bm.user_username;
            q.Title = bm.user_username;
            ql.Add(q);
        }

我得到的错误是： LINQ to Entities中仅支持无参数构造函数和初始值设定项

我不知道如何解决这个问题。 有任何想法吗？

Answer 1

在执行查询之前构造Guid：

Guid userGuid = new Guid(userid.ToString()); // What type is userid anyway?

var bms = 
     from b in context.bookmark
     join q in context.question1Set on b.bookmark_id equals q.question_id
     join u in context.userinfo on b.bookmark_ownerid equals u.user_userid
     where b.bookmark_ownerid == userGuid && !q.question_isdeleted
     select new
     {
         u.user_username,
         q.question_title
     };