Question

这有效：

var model =
   (from t in _db.Tickets
   from p in _db.Cust
   where t.Id == 5 && t.Id == p.cust_id
   orderby t.Id descending
   select new tks_custs
   {
       Tks = t,
       Custs = p
   });

但我希望通过以下方式实现这样的目标：

var model = _db.Tickets
    .Join(_db.Cust,
        t => t.Id,
        w => w.cust_id,
        (t, w) => new { Tks = t, Custs = w })
    .Where(t => t.Tks.Id == 5).OrderByDescending(w => w.Tks.Id)
    .GroupBy(t => t.Tks.Name).ToList();

我的观点声明目前是：

 @model IQueryable<test.ViewModels.tks_custs>

Answer 1

您应该像第一次查询一样创建VieModel对象（tks_custs）。现在您尝试传递DB模型（实际上不是BD模型，而是匿名IGrouping对象）。

它应该是这样的：

var model = _db.Tickets
            .Join(_db.Cust,
                t => t.Id,
                w => w.cust_id,
                (t, w) => new { Tks = t, Custs = w })
            .Where(t => t.Tks.Id == 5).OrderByDescending(w => w.Tks.Id)
            .GroupBy(t => t.Tks.Name).ToList()
            .Select(x => new tks_custs //here you creating your ViewModel
            {
                Tks = x.FirstOrDefailt().Tks,
                Custs = x.FirstOrDefailt().Custs 
            });

您可能会注意到FirstOrDefailt()。你需要它，因为GroupBy你可能在组中有很多实体。

传递ef查询以进行查看

1 个答案: