從組密鑰獲取其他屬性

Question

我有另一個問題與LINQ，所以我想要做的是創建一個最好的推銷員列表。我的sold_items表，看起來像這樣

[ID] 
[Name] 
[Price] 
[Sold_date] 
[Salesman_ID] 

和Salesmans

[ID] 
[Login] 
[First_name] 
[Surname] 

我要總結所有的價格表中，每一個人業務員銷售，也有一個選項，按日期組它例如，最好這個月，或者本週

var query1 = from s in context.Archive 
      //join us in context.Users 
      //on s.Salesman.ID equals us.ID 
      group s by s.Salesman.ID 
      into g 
      orderby g.Sum(o => o.Price) descending 
      select new 
      { 
       Salesman_ID = g.Key, 
       Sale = g.Sum(o => o.Price), 
      }; 

工作正常，但我只得到salesman_ID，如何添加用戶First_name和Surname從Salesmans表？

Answer 1

你可以做這樣的事情：

var query1 = 
    from s in context.Archive 
    group s by s.Salesman into g 
    orderby g.Sum(o => o.Price) descending 
    select new 
    { 
     Salesman_ID = g.Key.ID, 
     Salesman_First_name = g.Key.First_name, 
     Salesman_Surname = g.Key.Surname, 
     Sale = g.Sum(o => o.Price), 
    }; 

，並限制它在我的具體日期，使用這樣的：

var query1 = 
    from s in context.Archive 
    where s.Sold_date >= minDate && s.Sold_date <= maxDate 
    group s by s.Salesman into g 
    orderby g.Sum(o => o.Price) descending 
    select new 
    { 
     Salesman_ID = g.Key.ID, 
     Salesman_First_name = g.Key.First_name, 
     Salesman_Surname = g.Key.Surname, 
     Sale = g.Sum(o => o.Price), 
    }; 

Answer 2

改變了當前行到這一點。

select new { Salesman_ID = g.Key, Salesman_First_Name = g.Key.First_name }; 

Answer 3

您可以按多列（所有你想要檢索的列）

var query1 = from s in context.Archive 
         //join us in context.Users 
         //on s.Salesman.ID equals us.ID 
          group s by new // group by multiple columns 
          { 
          s.Salesman.Id, 
          s.first_name, 
          s.surname, 
          } into g      
         orderby g.Sum(o => o.Price) descending 
         select new 
         { 
         Salesman_ID = g.Key, 
         FirstName = g.first_name, 
         Surname = g.surname, 
         Sale = g.Sum(o => o.Price), 
        };