的LINQ集团通过与点心查询多个列

Question

var fpslist = db.FPSinformations.Where(x => x.Godown_Code != null && x.Godown_Code == godownid).ToList(); 
     var data1 = fpslist.GroupBy(x => x.Ration_Card_Type1) 
      .Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count1) 
      }).ToList(); 
     var data2 = fpslist.GroupBy(x => x.Ration_Card_Type2) 
      .Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count2) 
      }).ToList(); 
     var data3 = fpslist.GroupBy(x => x.Ration_Card_Type3) 
      .Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count3) 
      }).ToList(); 
     var data4 = fpslist.GroupBy(x => x.Ration_Card_Type4) 
      .Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count4) 
      }).ToList(); 
     var data5 = fpslist.GroupBy(x => x.Ration_Card_Type5) 
      .Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count5) 
      }).ToList(); 

     var GodownRCCount = data1.Where(x => x.CardType_Name != null).ToList(); 
     var GodownRCCounts = GodownRCCount; 
     GodownRCCount = data2.Where(x => x.CardType_Name != null).ToList(); 
     GodownRCCounts.AddRange(GodownRCCount); 
     GodownRCCount = data3.Where(x => x.CardType_Name != null).ToList(); 
     GodownRCCounts.AddRange(GodownRCCount); 
     GodownRCCount = data4.Where(x => x.CardType_Name != null).ToList(); 
     GodownRCCounts.AddRange(GodownRCCount); 
     GodownRCCount = data5.Where(x => x.CardType_Name != null).ToList(); 
     GodownRCCounts.AddRange(GodownRCCount); 

我有10列在我的数据库就像

Ration_Card_Type1 
Ration_card_count1 
Ration_Card_Type2 
Ration_card_count2 
Ration_Card_Type3 
Ration_card_count3 
Ration_Card_Type4 
Ration_card_count4 
Ration_Card_Type5 
Ration_card_count5 

现在，我要的是从它的类型得到Ration_Card_Counts的总和及其类型

预期输出：

CardType_Name 
CardType_Count 

那么上面的代码工作正常，但我想以最大可能的方式对其进行优化，因为这将位于Loop中，并且有大约150万条记录。

感谢

Answer 1

可以使用SQL重写相同的查询，并把一些指标（性能）：

SELECT Ration_Card_Type = Ration_Card_Type1, Ration_Card_Count = sum(Ration_card_count1) 
FROM 
    FPSinformations 
GROUP BY 
    Ration_Card_Type1 
UNION 
SELECT Ration_Card_Type = Ration_Card_Type2, Ration_Card_Count = sum(Ration_card_count2) 
FROM 
    FPSinformations 
GROUP BY 
    Ration_Card_Type2 
UNION 
SELECT Ration_Card_Type = Ration_Card_Type3, Ration_Card_Count = sum(Ration_card_count3) 
FROM 
    FPSinformations 
GROUP BY 
    Ration_Card_Type3 
UNION 
SELECT Ration_Card_Type = Ration_Card_Type4, Ration_Card_Count = sum(Ration_card_count4) 
FROM 
    FPSinformations 
GROUP BY 
    Ration_Card_Type4 
UNION 
SELECT Ration_Card_Type = Ration_Card_Type5, Ration_Card_Count = sum(Ration_card_count5) 
FROM 
    FPSinformations 
GROUP BY 
    Ration_Card_Type5 

我不知道，但此查询让我想想UNPIVOT也许你可以调查在这方面也是如此。

Answer 2

联盟应该比AddRange运行得更快！ 你可以尝试以下方法：

var data = (from g in fpslist.GroupBy(x => x.Ration_Card_Type1).Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count1) 
      }).Union(
       fpslist.GroupBy(x => x.Ration_Card_Type2).Select(x => new 
       { 
        CardType_Name = x.Key, 
        CardType_Count = x.Sum(y => y.Ration_Card_Count2) 
       })).Union(
       fpslist.GroupBy(x => x.Ration_Card_Type3).Select(x => new 
       { 
        CardType_Name = x.Key, 
        CardType_Count = x.Sum(y => y.Ration_Card_Count3) 
       })).Union(
      fpslist.GroupBy(x => x.Ration_Card_Type4).Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count4) 
      })).Union(
      fpslist.GroupBy(x => x.Ration_Card_Type5).Select(x => new 
      { 
       CardType_Name = x.Key, 
       CardType_Count = x.Sum(y => y.Ration_Card_Count5) 
      })) 
         select g).ToList(); 

一般从分组我与托马斯去！ 数据库分组对我而言要好得多，因为您正在获取所需的聚合数据，因此通过网络传输的数据要少得多！