c# - 嵌套的 LINQ 查询，错误信息

Question

我目前正尝试在 linq 中执行嵌套查询，但我收到一条错误消息:

var subcatquery = from categories in mydb.Categories
                  where categories.ParentId == null
                  select new
                  {
                      category = categories.Name,
                      subcat = (from sub in mydb.Categories
                                where sub.ParentId == sub.Id
                                select new
                                {
                                    subcatItem = sub.Name,
                                    subcatId = sub.Id
                                 })
                    };

结果 View = The type '<>f__AnonymousType0<subcatItem,subcatId>' exists in both 'myapplication.dll' and 'System.Web.dll'

我不明白为什么..如果我删除子查询并将其放在它自己的...它完全没问题。

subcat类型是 collection<> ，这是问题所在吗？

    class categoryGroup 
    {
        public string category;
        public Collection<subcategoryGroup> subcat;

    }
    class subcategoryGroup
    {
        public string subcatItem;
        public int subcatId;

    }

Answer 1

在我的项目中，我使用如下所示的子查询

 var data = (from con in dbData.tblPresenters
                        where con.PresenterID == ID
                        select new
                        {
                            Name = con.Name,

                            Title = dbData.tblTitles.Where(x => x.TitleID == con.PresenterTitleID).FirstOrDefault()
                        }).ToList();

我想这对你有帮助......