EF核心联接使用包括但外键不是另一个表上的主键 [英] EF Core Join using Include but ForeignKey is not Primary Key on the other table

问题描述

我试图将我的表与另一端的ForeignKey和PrimaryKey相关联。但是现在我将使用不是该表的主要键的ForeignKey。我使用的是 [InverseProperty] ，但我认为它存在一个错误，因为我已经看了几个小时，而且所有人都说了同样的话。

I am trying to relate my Tables with ForeignKey and PrimaryKey on the other end. But now i will be using a ForeignKey which is not the primary for the said table. I was using [InverseProperty] but i think there's a bug with it since i've been looking around for hours already and all of them says the same thing about it.

文档表：

public class Document
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int DocumentId { get; set; }
    public int ProjectId { get; set; }
    public int DepartmentId { get; set; }
    public int AuthorId { get; set; }

    [NotMapped]
    public virtual User Author { get; set; }
}

用户

public class User
{
    [Key]
    public int UserId { get; set; }
    public int AuthUserId { get; set; }
    public string DisplayName { get; set; }

    [NotMapped]
    [ForeignKey("AuthorId")]
    public virtual Document Document { get; set; }
}

上下文：

modelBuilder.Entity<User>(entity =>
        {
            entity.HasOne(u => u.Document)
            .WithMany("AuthorId");
        });

我正在尝试使用他们此处，但没有运气。

I am trying to use the solution they here, but no luck.

任何帮助将不胜感激。谢谢！

Any help would really be appreciated. Thanks!

推荐答案

但是现在我将使用ForeignKey，它不是所说的主键表。

But now i will be using a ForeignKey which is not the primary for the said table.

为此，您可以使用EF Core 备用键功能。但是首先请按照以下说明正确设置模型类：（正如您所说，用户将有多个 Document ）

To do this you can use EF Core Alternate Keys feature. But first correct your model class set up as follows: (As you said a User will have multiple Document)

public class Document
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int DocumentId { get; set; }
    public int ProjectId { get; set; }
    public int DepartmentId { get; set; }
    public int AuthorId { get; set; }

    public User Author { get; set; }
}

public class User
{
    [Key]
    public int UserId { get; set; }
    public int AuthUserId { get; set; }
    public string DisplayName { get; set; }


    public ICollection<Document> Documents { get; set; }
}

然后使用 Fluent API 配置如下：

modelBuilder.Entity<Document>()
        .HasOne(p => p.Author)
        .WithMany(b => b.Documents)
        .HasForeignKey(p => p.AuthorId)
        .HasPrincipalKey(b => b.AuthUserId); // <-- here you are specifying `AuthUserId` as `PrincipalKey` in the relation which is not primary key

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