实体框架:具有复数不规则名称的模型配置

本文关键字：模型 配置 不规则 框架 实体 | 更新日期: 2023-09-27 18:35:07

我有一个用 ASP.NET MVC4，EntityFramework Code First和Razor编写的系统。其中一个模型具有以下语句：

public class Flour : IEntityBase
{
    [Key]
    public Guid FlourId { get; set; }
    public Guid ProcessId { get; set; }
    [Display(Name = "Timestamp", ResourceType = typeof(Resources.Language))]
    [Timestamp]
    public Byte[] Timestamp { get; set; }
    [Display(Name = "FlourAnalyzes", ResourceType = typeof(Resources.Language))]
    public virtual ICollection<FlourAnalysis> FlourAnalyzes { get; set; }
    [Display(Name = "Process", ResourceType = typeof(Resources.Language))]
    public virtual Process Process { get; set; }
    [Display(Name = "LastModified", ResourceType = typeof(Resources.Language))]
    public DateTime LastModified { get; set; }
    [Display(Name = "CreatedOn", ResourceType = typeof(Resources.Language))]
    public DateTime CreatedOn { get; set; }
}

如前所述，Flour有一个 FlourAnalysis .该模型描述如下：

[Table(name: "FlourAnalyzes")]
public class FlourAnalysis : IEntityBase
{
    [Key]
    public Guid FlourAnalysisId { get; set; }
    public Guid FlourId { get; set; }
    public Guid? MeshId { get; set; }
    [Display(Name = "Timestamp", ResourceType = typeof(Resources.Language))]
    [Timestamp]
    public Byte[] Timestamp { get; set; }
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd hh:mm}", ApplyFormatInEditMode = true)]
    [Display(Name = "StartTimestamp", ResourceType = typeof(Resources.Language))]
    public DateTime? StartTimestamp { get; set; }
    [Display(Name = "HumidityPercentage", ResourceType = typeof(Resources.Language))]
    [Range(0, 100)]
    public Double HumidityPercentage { get; set; }
    [Display(Name = "StarchPercentage", ResourceType = typeof(Resources.Language))]
    [Range(0, 100)]
    public Double StarchPercentage { get; set; }
    [DataType(DataType.MultilineText)]
    [Display(Name = "Comments", ResourceType = typeof(Resources.Language))]
    public String Comments { get; set; }
    [Display(Name = "Flour", ResourceType = typeof(Resources.Language))]
    public virtual Flour Flour { get; set; }
    [Display(Name = "Mesh", ResourceType = typeof(Resources.Language))]
    public virtual Mesh Mesh { get; set; }
    [Display(Name = "LastModified", ResourceType = typeof(Resources.Language))]
    public DateTime LastModified { get; set; }
    [Display(Name = "CreatedOn", ResourceType = typeof(Resources.Language))]
    public DateTime CreatedOn { get; set; }
    public FlourAnalysis() {
        this.HumidityPercentage = 0;
        this.StarchPercentage = 0;
    }

生成迁移后，EF 创建了一个名为 FlourAnalyzes 的表（我需要强制使用表名，否则 EF 将以单数形式创建表）。在其中插入一些数据后，EF 不会通过上下文引入FlourAnalysis数据调用Flour对象：

[Authorize]
public ViewResult Details(System.Guid id)
{
    var flour = context.Flours
        .Include(f => f.FlourAnalyzes)
        .Single(x => x.FlourId == id);
    return View(flour);
}

编辑：

经过一些建议，我将.Single()表达式更改为.Where()，生成的SQL指向甚至不应该存在的列，Flour_ProcessId：

{SELECT 
[Project1].[C1] AS [C1], 
[Project1].[ProcessId] AS [ProcessId], 
[Project1].[FlourId] AS [FlourId], 
[Project1].[Timestamp] AS [Timestamp], 
[Project1].[LastModified] AS [LastModified], 
[Project1].[CreatedOn] AS [CreatedOn], 
[Project1].[Mesh_MeshId] AS [Mesh_MeshId], 
[Project1].[C2] AS [C2], 
[Project1].[FlourAnalysisId] AS [FlourAnalysisId], 
[Project1].[FlourId1] AS [FlourId1], 
[Project1].[MeshId] AS [MeshId], 
[Project1].[Timestamp1] AS [Timestamp1], 
[Project1].[StartTimestamp] AS [StartTimestamp], 
[Project1].[HumidityPercentage] AS [HumidityPercentage], 
[Project1].[StarchPercentage] AS [StarchPercentage], 
[Project1].[Comments] AS [Comments], 
[Project1].[LastModified1] AS [LastModified1], 
[Project1].[CreatedOn1] AS [CreatedOn1], 
[Project1].[Flour_ProcessId] AS [Flour_ProcessId]
FROM ( SELECT 
    [Extent1].[ProcessId] AS [ProcessId], 
    [Extent1].[FlourId] AS [FlourId], 
    [Extent1].[Timestamp] AS [Timestamp], 
    [Extent1].[LastModified] AS [LastModified], 
    [Extent1].[CreatedOn] AS [CreatedOn], 
    [Extent1].[Mesh_MeshId] AS [Mesh_MeshId], 
    1 AS [C1], 
    [Extent2].[FlourAnalysisId] AS [FlourAnalysisId], 
    [Extent2].[FlourId] AS [FlourId1], 
    [Extent2].[MeshId] AS [MeshId], 
    [Extent2].[Timestamp] AS [Timestamp1], 
    [Extent2].[StartTimestamp] AS [StartTimestamp], 
    [Extent2].[HumidityPercentage] AS [HumidityPercentage], 
    [Extent2].[StarchPercentage] AS [StarchPercentage], 
    [Extent2].[Comments] AS [Comments], 
    [Extent2].[LastModified] AS [LastModified1], 
    [Extent2].[CreatedOn] AS [CreatedOn1], 
    [Extent2].[Flour_ProcessId] AS [Flour_ProcessId], 
    CASE WHEN ([Extent2].[FlourAnalysisId] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
    FROM  [dbo].[Flours] AS [Extent1]
    LEFT OUTER JOIN [dbo].[FlourAnalyzes] AS [Extent2] ON [Extent1].[ProcessId] = [Extent2].[Flour_ProcessId]
WHERE [Extent1].[FlourId] = @p__linq__0
)  AS [Project1]
ORDER BY [Project1].[ProcessId] ASC, [Project1].[C2] ASC}

我做错了什么？

实体框架:具有复数不规则名称的模型配置

为了避免您遇到的错误Process_ProcessId您需要添加一个属性：

[ForeignKey("ProcessId")]
public virtual Process Process { get; set; }

这是因为生成外键的约定将使用错误的列名。

你可能还需要在FlourAnalysis课上这样的东西：

[ForeignKey("FlourId")]
public virtual Flour Flour { get; set; }
[ForeignKey("MeshId")]
public virtual Mesh Mesh { get; set; }

请注意，在所有情况下，我都省略了代码中的其他属性，只是为了突出显示我添加的内容。

这是一篇古老的文章，解释了如何使用该属性。

使用预先存在的数据库以查看是否已正确定义映射的有用提示是安装 EF 高级工具并使用"查看实体数据模型 DDL SQL"选项查看 EF 认为数据库的外观。 如果生成的 SQL 与实际数据库不匹配，则知道需要修改模型注释或配置。

默认情况下，实体框架将假定数据库中表的所有名称都是复数的，或者在代码优先的情况下，您希望它们在创建时是复数的。

检查这个希望它会有所帮助

http://edspencer.me.uk/2012/03/13/entity-framework-plural-and-singular-table-names/

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