c# - LINQ to Entities 无法识别方法 'System.Object get_Item(System.String)'

Question

下面出现错误

LINQ to Entities does not recognize the method 'System.Object get_Item(System.String)' method, and this method cannot be translated into a store expression

尝试从数据库获取 Postobject 的数据并将其发送为 Json 格式。 PostComments是Post的一对多关系。 我首先使用 EF 5.x 代码。

    try
        {
            IEnumerable<Post> userPosts;
            userPosts = (from q in db.Posts
                         where q.UserId == userId
                         && q.PostId > postid
                         select q).Take(5);


            return Json(userPosts.Select(x => new
            {
                success = 1,
                contenttext = x.PostContent,
                postId = x.PostId,
                comments = x.PostComments  //is a child collection object
            }), JsonRequestBehavior.AllowGet);

        }
        catch (Exception ex)
        {
            return Json(new { success = 0 });

        }
        finally
        {
            //db.Dispose();
        }

Answer 1

我不确定你是否已经尝试过这个。

return Json(userPosts.Select(x => new
        {
            success = 1,
            contenttext = x.PostContent,
            postId = x.PostId,
            comments = x.PostComments  //is a child collection object
        }).ToList(), JsonRequestBehavior.AllowGet);