LINQ的次數在過去每週首先會檢查數量的，從28周直到本週

Question

我有一個名爲SQL表瞭解它代表了物理治療師

ConsultID ConsultDate Therapist Location 

的諮詢誰（治療），我想提出這個數據彙總每星期，開始27周前，直到本週

像：

Location  Week-1   Week-2   Week-3 .....  Week-28 
Amsterdam 41    38    34    55 

Utrecht  65    56    46    46 

我怎樣才能做到這一點的LINQ？我有以下幾點：

public ActionResult Therapist(int? id) 
    { 
     if (id == null) 
     { 
      return new HttpStatusCodeResult(HttpStatusCode.BadRequest); 
     } 

     DateTime startDate = DateTime.Now.StartOfWeek(DayOfWeek.Monday).AddDays(-168); 
     DateTime endDate = DateTime.Now.StartOfWeek(DayOfWeek.Sunday); 

     var TherapistConsult = from row in db.Consults 
           where ((row.Therapist == id) && (row.ConsultDate > startDate) && (row.ConsultDate < endDate)) 
           group row by row.Location into g 
           where g.FirstOrDefault() != null 
           select new 
           { 
            Location = g.Key, 
            // Need a loop here for 28 weeks in the past till this week 
            // WeekN = g.Count(x => x.Week == N), 

           }; 

     return View(TherapistConsult.ToList()); 

    } 

Answer 1

什麼你要找的是「樞軸」你的數據，這是很容易從SQL做然後從LINQ，
在CodeProject上
看這件事 http://www.codeproject.com/Tips/500811/Simple-Way-To-Use-Pivot-In-SQL-Query
而如果你有在LINQ由於某種原因，要做到這一點，看看這件事：
Pivot data using LINQ