asp.net - Entity Framework 4与ctp5和脏生成的sql

Question

我在 ef4 ctp5 中遇到奇怪的生成 SQL 问题。

我有带有映射的简单模型:

[Table("post_auction")]
public class PostAuction
{
    [Key,Column(Name="Id"),DatabaseGenerated(System.ComponentModel.DataAnnotations.DatabaseGenerationOption.Identity)]
    public int Id { get; set; }

    [Column(Name = "Number")]
    public int Number { get; set; }

    [Column(Name = "Label")]
    public string Label { get; set; }

    [Column(Name = "Description")]
    public string Description { get; set; }

    [Column(Name = "CategoryId")]
    public int PostAuctionCategoryId { get; set; }

    [Column(Name = "PriceCZK")]
    public int PriceCZK { get; set; }

    [NotMapped]
    public bool IsAuctionPhotoExitst
    {
        get
        {
            if (File.Exists(HttpContext.Current.Server.MapPath("~/Public/Images/Posts/Thumbs/small_" + this.Number + ".jpg")))
                return true;
            return false;
        }
    }
}

我的 linq 查询是:

_rovastampDbContext.PostAuctions.Where(x => x.PostAuctionCategoryId == auctionId).OrderBy(x => x.Id).ToList();

Ef4 探查器向我展示

SELECT   
    [Project1].[Id]          AS [Id],
    [Project1].[Number]      AS [Number],
    [Project1].[Label]       AS [Label],
    [Project1].[Description] AS [Description],
    [Project1].[CategoryId]  AS [CategoryId],
    [Project1].[PriceCZK]    AS [PriceCZK]
FROM
    (SELECT 
         [Extent1].[Id]          AS [Id],
         [Extent1].[Number]      AS [Number],
         [Extent1].[Label]       AS [Label],
         [Extent1].[Description] AS [Description],
         [Extent1].[CategoryId]  AS [CategoryId],
         [Extent1].[PriceCZK]    AS [PriceCZK]
     FROM   
         [dbo].[post_auction] AS [Extent1]
     WHERE  
         [Extent1].[CategoryId] = 1 /* @p__linq__0 */) AS [Project1]
     ORDER BY 
         [Project1].[Id] ASC

我的问题非常简单:为什么 ef4 会生成那个复杂的查询，而正确的查询是

SELECT ... 
FROM TABLE 
WHERE CategoryId = 1 
ORDER BY Id ASC

谢谢你的建议:)

马丁

编辑:如果我让 EF 自动创建数据库，查询问题仍然存在...

Answer 1

很好的问题。我猜测这是一个错误，因为我的(edmx 生成的) Entity Framework 上下文不会像您的那样生成投影。我会将其报告为错误。