Question

我有一个可以有多个事件日期的事件表。我已经对这个错误进行了一些研究，但看起来我已经正确设置了所有内容，但是我对代码第一种方法不熟悉，而且我认为我的困惑在于覆盖了OnModelCreating

One or more validation errors were detected during model generation:

Event_EventDates_Source_Event_EventDates_Target: : The number of properties in the Dependent and Principal Roles in a relationship constraint must be identical.



[Table("EventDates")]
public class EventDate
{
    [Key, Column(Order=1)]
    public int EventDateId { get; set; }
    [Key, Column(Order = 2)]
    public DateTime EventDateStart { get; set; }
    public DateTime? EventEnd { get; set; }
    public string TicketPurchaseUrl { get; set; }
}

[Table("Events")]
public class Event
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int EventId { get; set; }
    ...
    public int EventDateId { get; set; }
    public DateTime EventDateStart { get; set; }
    [ForeignKey("EventDateId, EventDateStart")]
    public virtual ICollection<EventDate> EventDates { get; set; }
}

Answer 1

对于您描述的业务逻辑，您的模型有点奇怪。如果Event可以有多个EventDates，则Event中的外键不应该引用EventDate，反之亦然：{{1}中的外键} {}引用EventDate，也可能是Event中的导航属性Event：

EventDate

按惯例，[Table("EventDates")] public class EventDate { public int EventDateId { get; set; } public int EventId { get; set; } [ForeignKey("EventId")] public Event Event { get; set; } public DateTime EventDateStart { get; set; } public DateTime? EventEnd { get; set; } public string TicketPurchaseUrl { get; set; } } [Table("Events")] public class Event { public int EventId { get; set; } public virtual ICollection<EventDate> EventDates { get; set; } }和EventDate.EventDateId将成为密钥，它们将自动生成。我建议您省去Event.EventId中DateTime作为复合键的一部分的麻烦。如果你真的不需要这样的复合键，只需要EventDate身份作为键就可以保持简单。

具有多个密钥的EF Code First外键

1 个答案: