EF 4.1 EntityType 没有键 - 复合

Question

我刚刚使用 NuGet 升级到最新的 EF 4.1 代码优先，现在收到有关映射的错误。

我有这个类

public class UserApplication
{
    [Key, Column(Order = 0)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int UserId { get; set; }

    [Key, Column(Order = 1)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int ApplicationId { get; set; }

    [ForeignKey("ApplicationId")]
    public virtual Application Application { get; set; }

    public DateTime SubscribedDate { get; set; }
}

并且我收到此错误：

System.Data.Edm.EdmEntityType: : EntityType 'UserApplication' has no key defined. Define the key for this EntityType.
System.Data.Edm.EdmEntitySet: EntityType: EntitySet 'UserApplications' is based on type 'UserApplication' that has no keys defined.

但是我可以使用像这样的 Fluent API 使其工作

modelBuilder.Entity<UserApplication>().HasKey(obj => new {obj.UserId, obj.ApplicationId });

为什么 EF 没有拾取我使用注释定义的复合键？ 我非常确定这曾经适用于较旧的 EF 4.1。

Answer 1

适用于实体框架 6.1.3。我还添加了一个基本的 Application 类，但按原样使用了 UserApplication（DatabaseGeneratedOption 除外）。生成了以下 SQL：

CREATE TABLE [dbo].[UserApplication] (
    [UserId] [int] NOT NULL,
    [ApplicationId] [int] NOT NULL,
    [SubscribedDate] [datetime] NOT NULL,
    CONSTRAINT [PK_dbo.UserApplication] PRIMARY KEY ([UserId], [ApplicationId])
)


CREATE TABLE [dbo].[Application] (
    [ApplicationId] [int] NOT NULL IDENTITY,
    [Name] [nvarchar](max),
    CONSTRAINT [PK_dbo.Application] PRIMARY KEY ([ApplicationId])
)

Answer 2

我已经解决了这个问题。我刚刚添加了额外的关键列：

public class AlbumUser
{
    public Album Album
    {
        get;
        set;
    }

    public IdentityUser User
    {
        get;
        set;
    }

    [Key]
    [Column(Order = 0)]
    [StringLength(128)]
    public string UserId
    {
        get;
        set;
    }

    [Key]
    [Column(Order = 1)]
    public int AlbumId
    {
        get;
        set;
    }
}