linq - 特定区域的最大和最小速率 - lambda 查询

Question

我的表看起来像 -
   Area MaxRate MinRate Quarter year
    过境 1000 800 1 2013
    过境 900 700 2 2013
    过境 800 600 3 2013

    过境 700 500 4 2013
    过境 600 500 1 2012
    过境 550 450 2 2012
    过境 500 400 3 2012

    过境 450 350 4 2012
    内降 2000 1500 1 2013
    内降 1800 1500 2 2013


 I want max and min rates for the particular area in current year as -

 **Area    MaxRate  MinRate       year**
 crossing  1000     500           2013

请帮我在 LINQ-lambda 表示法中找到查询

Answer 1

您可以使用它GroupBy来执行此操作：

var results = table.GroupBy(row => new { Area = row.Area, Year = row.year })
                   .Select(g => new { 
                                       Area = g.Key.Area, 
                                       MaxRate = g.Max(i => i.MaxRate),
                                       MinRate = g.Min(i => i.MinRate),
                                       Year = g.Key.Year
                                    });