Linq查询选择顶级记录

Question

我有IEnumerable<MyData>哪些包含以下数据

Fruits | Name | Quantity | 
__________________________
 Mango | Jay  |    10    |
__________________________
 Apple | Jay  |    16    |
__________________________
 Grapes| Jay  |    12    |
__________________________
 Mango | Raj  |    11    |
__________________________
 Apple | Raj  |    20    |
__________________________
 Grapes| Raj  |    3     |
__________________________
 Mango | Vik  |    20    |
__________________________
 Apple | Vik  |    15    |
__________________________

我需要根据名称从Linq顶部选择两个数量

Jay (10+16+12) = 38
Raj (11+20+3) = 34
Vik (20+15) = 35

Jay和Vik有两个数量之和,所以我需要这些记录

Fruits | Name | Quantity | 
__________________________
 Mango | Jay  |    10    |
__________________________
 Apple | Jay  |    16    |
__________________________
 Grapes| Jay  |    12    |
__________________________
 Mango | Vik  |    20    |
__________________________
 Apple | Vik  |    15    |
__________________________

Answer 1

听起来像你可能想要的东西:

var query = from item in collection
            group item by item.Name into g
            orderby g.Sum(x => x.Quantity)  descending
            select g;
var topTwo = query.Take(2);

这将采用前两组,因此您将其用作:

foreach (var group in topTwo)
{
    Console.WriteLine("Name: {0}", group.Key);
    foreach (var item in group)
    {
        Console.WriteLine("  {0}: {1}", item.Fruits, item.Quantity);
    }
}