實體框架4困難的查詢與未映射的屬性

Question

我是EF的新手，我認爲有時候更容易犧牲ORM的優勢。但我想知道是否有方法使用EF4來執行此查詢。

我有datawarehouse事實表。映射看起來像

public class GameResult 
    { 
     [Key] 
     public int GameResultId { get; set; } 

     public virtual Competition Competition { get; set; }  

     public virtual CustomDate DateGame { get; set; }  

     public virtual Contender ContenderFirst { get; set; } 

     public virtual Contender ContenderSecond { get; set; } 

     public virtual Location Location { get; set; } 

     public int ScoreContenderFirst { get; set; } 

     public int ScoreContenderSecond { get; set; } 

     public int PrizeStock { get; set; } 

     public int Budget { get; set; } 

     [NotMapped] 
     public int WinCount { get; set; } 

     [NotMapped] 
     public int FailCount { get; set; } 

     [NotMapped] 
     public int DeadHeatCount { get; set; } 

     [NotMapped] 
     public int CountGames { get; set; } 
    } 

和查詢上sql

select 
    Contenders.Name, 
    sum((Case 
     when (ScoreContenderFirst > ScoreContenderSecond) then 1 
     else 0 
    end)) as wins, 
    sum ((Case 
     when (ScoreContenderFirst = ScoreContenderSecond) then 1 
     else 0 
    end)) as equals, 
    sum((Case 
     when (ScoreContenderFirst < ScoreContenderSecond) then 1 
     else 0 
    end)) as fail, 
    COUNT(GameResults.GameResultId)as countGames 
from GameResults 
inner join Contenders 
on GameResults.ContenderSecond_ContenderId = Contenders.ContenderId 
where GameResults.ContenderFirst_ContenderId = 42 
group by Contenders.Name 
UNION 
select 
    Contenders.Name, 
    sum((Case 
     when (ScoreContenderFirst < ScoreContenderSecond) then 1 
     else 0 
    end)) as wins, 
    sum ((Case 
     when (ScoreContenderFirst = ScoreContenderSecond) then 1 
     else 0 
    end)) as equals, 
    sum((Case 
     when (ScoreContenderFirst > ScoreContenderSecond) then 1 
     else 0 
    end)) as fail, 
    COUNT(GameResults.GameResultId)as countGames 
from GameResults 
inner join Contenders 
on GameResults.ContenderFirst_ContenderId = Contenders.ContenderId 
where GameResults.ContenderSecond_ContenderId = 42 
group by Contenders.Name 

這sql查詢手段（我希望得到一個特定的球隊與其他球隊的比賽結果（一些遊戲，特定隊是冠軍，以及特定隊伍放鬆的比賽數量））

Answer 1

_efContext.GameResult 
      .Where(game => game.ContenderFirst_ContenderId == 42) 
      .Select(game => new { 
        ContendersName = game.ContenderFirst.Name 
        , Win = game.ScoreContenderFirst > game.ScoreContenderSecond 
        , Draw = game.ScoreContenderFirst == game.ScoreContenderSecond 
        , Lose = game.ScoreContenderFirst < game.ScoreContenderSecond 
        }) 
      .GroupBy(game => game.ContendersName) 
      .Select(grp => new { 
        ContendersName= grp.Key 
       , Wins = grp.Where(game => game.Win).Count() 
       , Draws = grp.Where(game => game.Draw).Count() 
       , Loses = grp.Where(game => game.Lose).Count() 
      }) 

不包括countGames，因爲它只是勝利，抽獎的總和並失去。

對於第二個，你可以用這個查詢看起來像第一個連接：

_efContext.GameResult 
      .Where(game => game.ContenderSecond_ContenderId == 42) 
      .Select(game => new { 
       ContendersName = game.ContenderSecond.Name 
       , Win = game.ScoreContenderFirst < game.ScoreContenderSecond 
       , Draw = game.ScoreContenderFirst == game.ScoreContenderSecond 
       , Lose = game.ScoreContenderFirst > game.ScoreContenderSecond 
       }) 
      .GroupBy(game => game.ContendersName) 
      .Select(grp => new { 
       ContendersName= grp.Key 
      , Wins = grp.Where(game => game.Win).Count() 
      , Draws = grp.Where(game => game.Draw).Count() 
      , Loses = grp.Where(game => game.Lose).Count() 
     })