LINQ到实体，而不是存储过程？ [英] LINQ to Entities instead of stored procedure?

问题描述

我使用实体框架来访问我的数据库，我只是想通了，映射的存储过程使用实体的方法是有点太复杂，可能不太适合做我想做exacltly。我是新来的LINQ和我想知道如果我是前人的精力更好只是ADO.NET。下面是SQL代码，我需要翻译：

I am using the Entity Framework to access my database and I just figured out that mapping stored procedures to methods using entity is a bit too complex and probably not well suited to do what I want exacltly. I am new to LINQ and I am wondering if I sould be better off just with ADO.NET. Here is the SQL code I need to translate:

SELECT p.Player_id, p.Name, p.Position, SUM(s.Goals) AS goalsb, SUM(s.Assists) AS assistsb, SUM(s.Points) AS pointsb
FROM Dim_Player AS p INNER JOIN Fact_Statistics AS s ON s.Player_id = p.Player_id
GROUP BY p.Player_id, p.Name, p.Position
ORDER BY pointsb DESC, goalsb DESC

随着实体映射存储过程，我有这个代码写的：

With the Entities mapping for stored procedures, I had this code written:

HockeyStatsEntities db = new HockeyStatsEntities();

public ActionResult Index()
{
    ViewBag.Message = "League leaders";
    {
        return View(db.ListLeagueLeaders());
    }
}

public ActionResult About()
{
    return View();
}

private ICollection<ListLeagueLeaders_Result> ListLeagueLeaders()
{
    ICollection<ListLeagueLeaders_Result> leagueLeadersCollection = null;

    using (HockeyStatsEntities context = new HockeyStatsEntities())
    {
        foreach (ListLeagueLeaders_Result leagueLeader in
                  context.ListLeagueLeaders())
        {
            leagueLeadersCollection.Add(leagueLeader);
        }
    }
    return leagueLeadersCollection;
}

下面是我得到的错误：

传递到字典中的模型产品类型
的'System.Data.Objects.ObjectResult`1 [NHLStats2.Models.ListLeagueLeaders_Result]'，
，而这本词典需要输入
'NHLStats2.Models.ListLeagueLeaders_Result的典范项目。

The model item passed into the dictionary is of type 'System.Data.Objects.ObjectResult`1[NHLStats2.Models.ListLeagueLeaders_Result]', but this dictionary requires a model item of type 'NHLStats2.Models.ListLeagueLeaders_Result'.

但我知道这有一点在和放大器痛; * @ ......我怎么会用一种不同的，更有效的方法重新安排呢？ 。感谢您的帮助，这真是感激

But I realize that this is a bit of a pain in the ?&*@... How could I re-arrange this using a different, more effective method? Thanks for your help, it's really appreciated.

推荐答案

最后选择了使用存储过程，这个编译和作品：

Finally opting for using a stored procedure, this compiles and works:

Model1.tt.Context.cs （自动生成）

public DbSet<Dim_Date> Dim_Date { get; set; }
    public DbSet<Dim_Player> Dim_Player { get; set; }
    public DbSet<Dim_Team> Dim_Team { get; set; }
    public DbSet<Fact_Statistics> Fact_Statistics { get; set; }
    public DbSet<Dim_Game> Dim_Game { get; set; }

    public virtual ObjectResult<ListLeagueLeaders_Result> ListLeagueLeaders()
    {
        ((IObjectContextAdapter)this).ObjectContext.MetadataWorkspace.LoadFromAssembly(typeof(ListLeagueLeaders_Result).Assembly);

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<ListLeagueLeaders_Result>("ListLeagueLeaders");
    }

查看

@model System.Data.Objects.ObjectResult<NHLStats2.Models.ListLeagueLeaders_Result>

@{
    ViewBag.Title = "Index";
}

[...]

问题是与强类型的视图类型不匹配的System.Data.Objects.ObjectResult类型。是： @model NHLStats2.Models.ListLeagueLeaders_Result ，更改为： @model System.Data.Objects.ObjectResult< NHLStats2.Models.ListLeagueLeaders_Result> 干杯！

Problem was with the strongly typed view type not matching the System.Data.Objects.ObjectResult type. Was: @model NHLStats2.Models.ListLeagueLeaders_Result, changed to: @model System.Data.Objects.ObjectResult<NHLStats2.Models.ListLeagueLeaders_Result> Cheers!

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