LINQ to SQL收藏

1、LINQ group by分組匯總

public class TestData  {         public string Name{get;set;}          public int Count { get; set; }          public string BatNum { get; set; }  }

protected void Click(object sender, EventArgs e)  {          List<TestData> list = new List<TestData>();          list.Add(new TestData() { Name = "A", Count = 3, BatNum = "001" });          list.Add(new TestData() { Name = "A", Count = 3, BatNum = "001" });          list.Add(new TestData() { Name = "A", Count = 3, BatNum = "002" });          list.Add(new TestData() { Name = "b", Count = 3, BatNum = "001" });          list.Add(new TestData() { Name = "b", Count = 6, BatNum = "002" });          list.Add(new TestData() { Name = "b", Count = 3, BatNum = "003" });          list.Add(new TestData() { Name = "b", Count = 5, BatNum = "001" });          var query = from l in list                      group l by new { l.Name, l.BatNum } into g                      select new                      {                          Name = g.Key.Name,                          Count = g.Sum(a => a.Count),                          BatNum = g.Key.BatNum                      };          string result = "";          foreach (var q in query)          {              result += "Name=/"" + q.Name + "/"," + "Count=/"" + q.Count + "/"," + "BatNum=/"" + q.BatNum + " /"<br />";          }          Response.Write(result);  }   //結果：   Name="A",Count="6",BatNum="001 "  Name="A",Count="3",BatNum="002 "  Name="b",Count="8",BatNum="001 "  Name="b",Count="6",BatNum="002 "  Name="b",Count="3",BatNum="003 "  

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