从sql查询中使用linq计数和Groupby

我试图创建一个表来统计所有的订单，并将他们从一个表中分组到SQL到LINQ在谷歌图表的条形图中使用。从sql查询中使用linq计数和Groupby

Table`

Orders Status 
8  Created 
3  Delayed 
4  Enroute

SQL

SELECT Count (OrderID) as 'Orders', order_status FROM [ORDER] 
where order_status ='Created'OR order_status= 'Delayed' OR order_status='Enroute' 
group by order_status

控制器

public ActionResult GetChart() 
    { 
     var Orders = db.Order.Select(a => new { a.OrderID, a.order_status }) 
          .GroupBy(a => a.order_status); 

     return Json(Orders, JsonRequestBehavior.AllowGet); 
    }

这是显示不正确的结果LINQ的似乎是错误的。有人可以请指出我在正确的方向吗？我对此比较陌生。在此先感谢。

来源

2015-09-16 Lenn_Modecy23

从你的榜样，你有什么预期的结果？ – AnhTriet

这应该工作： -

var result = db.Order.Where(x => x.order_status == "Created" 
          || x.order_status == "Delayed" 
          || x.order_status == "Enroute") 
        .GroupBy(x => x.order_status) 
        .Select(x => new 
            { 
             order_status = x.Key, 
             Orders = x.Count() 
            });

或者如果你喜欢，然后查询语法： -

var result = from o in db.Order 
      where o.order_status == "Created" || o.order_status == "Delayed" 
       || o.order_status == "Enroute" 
      group o by o.order_status 
      select new 
        { 
         orderStatus = x.Key, 
         Counts = x.Count() 
        };

来源

2015-09-16 14:22:21

我想你想组由Status各组计算的订单总数（我构建了一个简单的控制台程序来演示）。我猜想的数据是：

Orders Status 
8  Created 
3  Delayed 
4  Enroute 
2  Created 
1  Delayed

Order.cs

public class Order 
{ 
    public Order(int orderId, string status) 
    { 
     OrderId = orderId; 
     Status = status; 
    } 

    public int OrderId { get; set; } 
    public string Status { get; set; } 
}

Program.cs的

class Program 
{ 
    static void Main(string[] args) 
    { 
     // Data 
     var orders = new List<Order> 
     { 
      new Order(8, "Created"), 
      new Order(3, "Delayed"), 
      new Order(4, "Enroute"), 
      new Order(2, "Created"), 
      new Order(1, "Delayed"), 
     }; 

     // Query 
     var query = orders 
      .GroupBy(x => x.Status) 
      .Select(x => new {Status = x.Key, Total = x.Count()}); 

     // Display 
     foreach (var item in query) 
     { 
      Console.WriteLine(item.Status + ": " + item.Total); 
     } 
     Console.ReadLine(); 
    } 
}

你需要专注在上的人是query。使用GroupBy后，您将获得一个组列表。对于每个组，Key是组的标准（这里是Status）。然后，我们调用Count()来获得该组中元素的总数。

所以，从上面的程序，输出应该是：

Created: 2 
Delayed: 2 
Enroute: 1

来源

2015-09-16 14:32:33 AnhTriet

从sql查询中使用linq计数和Groupby

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