Question

情况如下。有两种ElectricConsumer即CommercialConsumers＆amp; DomesticConsumers（Quaters）和一个Quater被分配给一个Employee。下面是我的代码但遇到异常。

无法确定EFcodefirstDemo.CodeFistModel.Quater和类型之间关联的主要结尾 EFcodefirstDemo.CodeFistModel.Employee。这个的主要目的必须使用以下任一方式显式配置关联关系流畅的API或数据注释。

我知道我在某些地方犯了错误，因为我是EF的新手。希望你能解决这个问题。

public class Employee
{
    public Employee()
    {
        MeterReadings = new List<MeterReading>();
        MeterReadings = new List<MeterReading>();
    }

    [Key]
    [Column(Order = 1)]

    public int EmployeeID { get; set; }
    [Key]
    [Column(Order = 2)]

    public Int64 EmployeeNo { get; set; }
    public String EmployeeName { get; set; }
    [DefaultValue(true)]
    public bool Gender { get; set; }
    [DefaultValue(true)]

    public bool HasResidence { get; set; }
    public bool IsInDivision { get; set; }

    public int? ManagerID { get; set; }
    public virtual Employee Manager { get; set; }


    public virtual Department Deparment { get; set; }
    public int QuaterID { get; set; }
    [ForeignKey("QuaterID")]
     public virtual Quater Quater { get; set; }

    public virtual ICollection<MeterReading> MeterReadings { get; set; }

}

public partial class ElectricConsumer
{
    [Key]
    public int ElectricConsumerID { get; set; }
    public String Area { get; set; }
    [MaxLength(350)]
    public String Address { get; set; }
    public virtual ICollection< Meter> Meters { get; set; }
}




public partial class Quater : ElectricConsumer
{

    public Quater()
    {
        //  Meters = new List<Meter>();
    }

    public int QuaterNo { get; set; }
    public int QuaterPortionNo { get; set; }
    public virtual Employee Employee { get; set; }


}

public partial class CommericalCustomer : ElectricConsumer
{
    public CommericalCustomer()
    {
        //   Meters = new List<Meter>();
    }
      public String Name { get; set; }
    [Index("NicIndex", IsUnique = true)]
    public Int64 NIC { get; set; }

    public int ShopNo { get; set; }


}


public partial class Meter
{
    public Meter()
    {
        InstalledDate = DateTime.Now;
        MeterReadings = new List<MeterReading>();
        ElectricBills = new List<ElectricBill>();
    }

    [Key]
    [Column(Order = 1)]
    public int MeterID { get; set; }
    [Key]
    [Column(Order = 2)]
    public int MeterNo { get; set; }
    [DefaultValue(1)]
    public int Phase { get; set; }

    public DateTime InstalledDate { get; set; }
    [DefaultValue(true)]
    public bool IsOperating { get; set; }

    public virtual ElectricConsumer ElectricConsumer { get; set; }
    public virtual ICollection<MeterReading> MeterReadings { get; set; }
    public virtual ICollection<ElectricBill> ElectricBills { get; set; }
}

Answer 1

启动该异常是因为您尝试配置一对一关系，但未指定哪个结尾是关系中的主体。 Principal end是将首先插入的，并且可以在没有依赖的情况下存在的那个。依赖结束是必须在主体之后插入的结尾，因为它具有主体的外键。要解决此特定问题，您可以使用Required数据注释（我认为Quater实体在这种情况下是依赖项）：

public partial class Quater : ElectricConsumer
{   
  //...    
  [Required]
  public virtual Employee Employee { get; set; }
}

无法确定类型之间关联的主要结束

1 个答案: