c# - Entity Framework 中的多个自引用关系

Question

我目前有一个名为 EmployeeDetails 的类，如下所示。

public class EmployeeDetails {

    public int EmployeeDetailsId { get; set; }
    public string Name { get; set; }
    public string Title { get; set; }

    [ForeignKey("Manager")]
    public int? ManagerId { get; set; }
    public virtual EmployeeDetails Manager { get; set; }
    [ForeignKey("LineManager")]
    public int? LineManagerId { get; set; }
    public virtual EmployeeDetails LineManager { get; set; }

}

我正在尝试添加 Manager 和 LineManager 属性，它们将引用相同类型的对象。当我尝试添加迁移时，出现以下错误:

无法确定类型 EmployeeDetails 和 EmployeeDetails 之间关联的主要端。

在添加 ManagerId、LineManagerId 和 LineManager 属性之前，Manager 属性按预期工作。

我该如何解决？

Answer 1

您必须指定关系的另一方。像这样:

public class EmployeeDetails
{

    public int EmployeeDetailsId { get; set; }
    public string Name { get; set; }
    public string Title { get; set; }

    [ForeignKey("Manager")]
    public int? ManagerId { get; set; }

    public virtual EmployeeDetails Manager { get; set; }

    [ForeignKey("LineManager")]
    public int? LineManagerId { get; set; }

    public virtual EmployeeDetails LineManager { get; set; }

    [ForeignKey("ManagerId")]
    public virtual ICollection<EmployeeDetails> ManagedEmployees { get; set; }

    [ForeignKey("LineManagerId")]
    public virtual ICollection<EmployeeDetails> LineManagedEmployees { get; set; }

}

生成的迁移

CreateTable(
    "dbo.EmployeeDetails",
    c => new
        {
            EmployeeDetailsId = c.Int(nullable: false, identity: true),
            Name = c.String(),
            Title = c.String(),
            ManagerId = c.Int(),
            LineManagerId = c.Int(),
        })
    .PrimaryKey(t => t.EmployeeDetailsId)
    .ForeignKey("dbo.EmployeeDetails", t => t.LineManagerId)
    .ForeignKey("dbo.EmployeeDetails", t => t.ManagerId)
    .Index(t => t.ManagerId)
    .Index(t => t.LineManagerId);

这是否解决了您的问题？