請教各位大大，我參考JOIN的程式碼如下～

List<UnSignListVModel> sv = new List<UnSignListVModel>();
List<UnSignListVModel> sv2 = new List<UnSignListVModel>();

sv = db.RepairFlows.Where(f => f.Status == "?")
.Join(db.RepairDtls, f => f.DocId, rd => rd.DocId,
(f, rd) => new
{
    f.DocId,
    f.UserId,
    f.Cls,
    rd.Cost,
    rd.EndDate,
    rd.CloseDate,
    rd.FailFactor,
    rd.DealDes,
    rd.DealState
})
.Join(db.Repairs, rd => rd.DocId, k => k.DocId,
(rd, k) => new
{
    rd.DocId,
    rd.UserId,
    rd.Cls,
    k.AccDpt,
    k.ApplyDate,
    k.AssetNo,
    rd.Cost,
    rd.EndDate,
    rd.CloseDate,
    rd.FailFactor,
    rd.DealDes,
    rd.DealState,
    k.TroubleDes
}).Where(k => k.ApplyDate >= v.Sdate && k.ApplyDate <= v.Edate)
.Join(db.Assets, k => k.AssetNo, at => at.AssetNo,
(k, at) => new
{
    k.DocId,
    k.UserId,
    k.Cls,
    k.AccDpt,
    k.ApplyDate,
    k.AssetNo,
    at.Cname,
    k.Cost,
    k.EndDate,
    k.CloseDate,
    k.TroubleDes,
    k.FailFactor,
    k.DealDes,
    k.DealState,
    at.Type,
    at.AssetClass
})
 .Join(db.Departments, k => k.AccDpt, c => c.DptId,
(k, c) => new
{
    k.DocId,
    k.UserId,
    k.Cls,
    k.AccDpt,
    k.ApplyDate,
    k.AssetNo,
    k.Cname,
    k.Cost,
    k.EndDate,
    k.CloseDate,
    k.TroubleDes,
    k.FailFactor,
    k.DealDes,
    k.DealState,
    k.Type,
    k.AssetClass,
    c.Name_C
})
.Join(db.AppUsers, k => k.UserId, u => u.Id,
(k, u) => new UnSignListVModel
{
    DocTyp = "請修",
    DocId = k.DocId,
    AccDpt = k.AccDpt,
    AccDptNam = k.Name_C,
    AssetNo = k.AssetNo,
    AssetName = k.Cname,
    Type = k.Type,
    ApplyDate = k.ApplyDate.Value,
    EndDate = k.EndDate,
    TroubleDes = k.TroubleDes,
    FailFactor = k.FailFactor,
    DealDes = k.DealDes,
    DealState = k.DealState,
    EngNam = null,
    ClsEmp = u.FullName,
    AssetClass = k.AssetClass
}).ToList();

其中不懂的是，為什麼每一段JOIN都要new那麼多東西出來，例如：DocId每一段JOIN都要new出來，這是一定要這樣寫嗎？有沒有更簡潔的寫法？
前面join與new出來的參數應該是為了在最後面輸出時可以接著呼叫用，是說每一段都new同樣的東西這是一定要的嗎？
我參考這樣的寫法，寫了一段如下：

List<MemberViewModel> mv = new List<MemberViewModel>();
db.MemberToPapers.Where(x => x.ConferenceId == ConferenceId && x.PaperId == PaperId && x.Role == Role)
    .Join(db.Members,
    m => m.MemberId,
    x => x.MemberId,
    (m, x) => new
    {
        m.ConferenceId,
        m.PaperId,
        x.MemberId,
        x.Name,
        x.Email,
        m.Role
    }).ToList()
    .ForEach(o => mv.Add(new MemberViewModel
    {
        ConferenceId = o.ConferenceId,
        PaperId = o.PaperId,
        MemberId = o.MemberId,
        Name = o.Name,
        Email = o.Email,
        RoleName = GetRole(o.Role)
    }));

我在想說(m, x)也可以改寫成如下：

(m, x) => new
{
    m,
    x
}).ToList()

或是(m, x)可以合併成一個變數輸出即可？這樣是不是比較簡潔？

另外一問，我參考以下這一篇文章，想要做所謂的Dynamic LINQ：
http://kevintsengtw.blogspot.com/2012/06/dynamic-linq-entity-framework-part3.html

public ActionResult Test1()
{
    using (NorthwindEntities db = new NorthwindEntities())
    {
        var query = db.Customers
            .Where("City == @0 and Orders.Count >= @1", "London", 10)
            .OrderBy("CustomerID desc")
            .Take(10);
        ViewData.Model = query.ToList();
        return View();
    }
}

然後我就把我的程式改寫成以下

db.MemberToPapers.Where("ConferenceId == @0 AND PaperId == @1 AND Role == @2", ConferenceId, PaperId, Role)
    .Join(db.Members,
    m => m.MemberId,
    x => x.MemberId,
    (m, x) => new
    {
        m.ConferenceId,
        m.PaperId,
        x.MemberId,
        x.Name,
        x.Email,
        m.Role
    }).ToList()
    .ForEach(o => mv.Add(new MemberViewModel
    {
        ConferenceId = o.ConferenceId,
        PaperId = o.PaperId,
        MemberId = o.MemberId,
        Name = o.Name,
        Email = o.Email,
        RoleName = GetRole(o.Role)
    }));

VS回報錯誤：'方法'Where'沒有任何多載使用4個引數'
不知道要如何修正才能改為Dynamic LINQ呢？