最大值和最小值率特定區域-Lambda查詢

Question

my table looks like- 
    Area MaxRate MinRate Quarter year 
    crossing 1000  800  1  2013 
    crossing 900  700  2  2013 
    crossing 800  600  3  2013
 
    crossing 700  500  4  2013 
    crossing 600  500  1  2012 
    crossing 550  450  2  2012 
    crossing 500  400  3  2012
 
    crossing 450  350  4  2012 
    indroper 2000  1500 1  2013 
    indroper 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 
 

請幫我找到LINQ，拉姆達符號查詢

Answer 1

您可以使用GroupBy做到這一點：

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 
            });