EF6 CodeFirst ForeignKey 属性映射未按预期工作

Question

我有一个多对一的情况，一个员工可以服务很多客户，每个客户由 1 名员工服务。在 Customer class 中，我使用 ForeignKey 属性将 SupportRep 映射到 EmployeeId，它给我一个错误。

public class Customer
{
    [Key]
    public int CustomerId { get; set; }
    ...

    public int? SupportRepId { get; set; }

    [ForeignKey("EmployeeId")]
    public virtual Employee SupportRep { get; set; }
}

public class Employee
{
    [Key]
    public int EmployeeId { get; set; }
    ...

    [ForeignKey("SupportRepId")]
    public virtual ICollection<Customer> Customers { get; set; }
}

我得到的错误是：

Error: The ForeignKeyAttribute on property 'SupportRep' on type 'SqlLiteChinook. Customer' is not valid. The foreign key name 'EmployeeId' was not found on the d ependent type 'SqlLiteChinook.Customer'. The Name value should be a comma separa ted list of foreign key property names.

但是，如果我将 Customer class 中的 EmployeeId 更改为 SupportRepId，它会起作用。

Customerclass中的外键不应该指向Employeeclass的EmployeeId吗？

请赐教。谢谢。

Answer 1

试试这个

public class Customer
{
    [Key]
    public int CustomerId { get; set; }
    ...

    public int? SupportRepId { get; set; }

    [ForeignKey("SupportRepId")]
    public virtual Employee SupportRep { get; set; }
}

public class Employee
{
    [Key]
    public int EmployeeId { get; set; }
    ...

    public virtual ICollection<Customer> Customers { get; set; }
}

Answer 2

你把事情搞混了。 Customer class 中的 [ForeignKey("EmployeeId")] 必须说明 class 中的哪个属性是 Employee 的外键。该属性不会在 Employee class.

中寻找外键

您的第二个错误是在 ICollection<Customer> 上声明外键。由于您有一对多关系，您的集合不能指向一个客户，它与多个客户有关系。因此，您的客户需要拥有员工的外键（每个客户 'points' 到一名员工），但员工不能包含客户的外键。

public class Customer
{
  [Key]
  public int CustomerId { get; set; }
  ...
  public int? SupportRepId { get; set; }

  [ForeignKey("SupportRepId")]
  public virtual Employee SupportRep { get; set; }
}

public class Employee
{
  [Key]
  public int EmployeeId { get; set; }
  ...
  public virtual ICollection<Customer> Customers { get; set; }
}

EF6 CodeFirst ForeignKey 属性映射未按预期工作

EF6 CodeFirst ForeignKey attribute mapping not working as expected

c#

sqlite

entity-framework

ef-code-first