使用LINQ to Entities编写嵌套联接

您可以使用手动联接模拟定义关系后EF的功能。您所需要的只是使用Group Join和投影。像这样的东西：

var result =    (from a in db.A     where a.Id == IDParameter     join b in db.B on a.Id equals b.AId into Bs     select new     {         a,         Bs = (from b in Bs  join c in db.C on b.Id equals c.BId into Cs  select new  {      b,      Cs =         (from c in Cs          join d in db.D on c.Id equals d.CId into Ds          select new          {   c,   Ds = Ds.ToList()          }).ToList()   }).ToList()     }).ToList();