c# - 具有未映射属性的实体框架 4 困难查询

Question

我是新手，EF我认为有时牺牲 ORM 的优势更容易。但我想知道是否有办法使用EF4.

我有带有事实表的数据仓库。映射看起来像

    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; } 
    }

并查询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

此sql查询的意思是（我想获取特定球队与其他球队的比赛结果（特定球队获胜的比赛数量，以及特定球队较松的比赛数量））

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，因为它只是胜利、平局和失败的总和。

对于第二个，你可以加入这个看起来像第一个的查询：

_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()
       })