Question

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

我有这个班级

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; }
}

我收到了这个错误：

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.

然而，我可以使用像这样的Fluent API

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

为什么EF没有拿起我使用注释定义的复合键？我很确定这曾经适用于较旧的EF 4.1。

Answer 1

我已经解决了这个问题。我刚刚添加了其他关键列：

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;
    }
}

Answer 2

与Entity Framework 6.1.3一起使用。我还添加了一个基本的Application类，但按原样使用了UserApplication（DatabaseGenerat ed 选项除外。这个SQL是生成的：

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])
)

EF 4.1 EntityType没有键 - 复合

2 个答案: