EF6 生成奇怪的外键

Question

我在使用 EF 6 时遇到了一点问题。这些是我的模型（好吧，我省略了不相关的属性）：

[Table("Departments")]
public class Department
{
    public string Id { get; set; }

    public string Name { get; set; }
    public string Description { get; set; }

    public IList<Staff> Staff { get; set; }

    public Staff HOD { get; set; }
}

[Table("Staff")]
public class Staff
{
    [Key]
    public string EmployeeId { get; set; }

    public string Name { get; set; }

    public Department Department { get; set; }
}

这是 EF6 正在生成的迁移（嗯，只是创建方法）：

CreateTable(
    "dbo.Staff",
    c => new
        {
            EmployeeId = c.String(nullable: false, maxLength: 128),
            Name = c.String(),
            Department_Id = c.String(maxLength: 128),
            Department_Id1 = c.String(maxLength: 128),
        })
    .PrimaryKey(t => t.EmployeeId)
    .ForeignKey("dbo.Departments", t => t.Department_Id)
    .ForeignKey("dbo.Departments", t => t.Department_Id1)
    .Index(t => t.Department_Id)      //what's this?
    .Index(t => t.Department_Id1);    //what's this?

CreateTable(
    "dbo.Departments",
    c => new
        {
            Id = c.String(nullable: false, maxLength: 128),
            Name = c.String(),
            Description = c.String(),
            HOD_EmployeeId = c.String(maxLength: 128),
        })
    .PrimaryKey(t => t.Id)
    .ForeignKey("dbo.Staff", t => t.HOD_EmployeeId)
    .Index(t => t.HOD_EmployeeId);

看看生成的外键。似乎有些不对劲。我该如何纠正这个问题？

Answer 1

尝试添加一些关系

[Table("Departments")]
public class Department
{
    public string Id { get; set; }

    public string Name { get; set; }
    public string Description { get; set; }

    public virtual IList<Staff> Staff { get; set; }

     public  int HodId {get set;}

     [ForeignKey("HodId")]
    public Staff Hod { get; set; }
}

[Table("Staff")]
public class Staff
{
    [Key]
    public string EmployeeId { get; set; }

    public string Name { get; set; }

    public int DepartmentId { get; set; }

    public virtual Department Department { get; set; }
}

Answer 2

我必须使用 Fluent API 来建立这种关系：

modelBuilder.Entity<Staff>()
    .HasRequired<Department>(staff => staff.Department)
    .WithMany(department => department.Staff)
    .HasForeignKey<string>(staff => staff.DepartmentId);

模型变化：

public Department Department { get; set; }

改为

public string DepartmentId { get; set; }
public virtual Department Department { get; set; }

和

public IList<Staff> Staff { get; set; }

public Staff HOD { get; set; }

改为

public virtual IList<Staff> Staff { get; set; }

public Staff HOD { get; set; }