在Fluent API中首先实现“零”或“一到零”或“一个关系” [英] Implementing Zero Or One to Zero Or One relationship in EF Code first by Fluent API

问题描述

我有两个POCO类

public class Order
{
  int id;
  string code;
  int? quotationId;  //it is foreign key
  public int Id{get;set;}
  public string Code{get;set;}
  public int? QuotationId{get;set;}
  Quotation quotation;
  public virtual Quotation Quotation { get; set; }
  ....
}

public class Quotation
{
  int Id;
  string Code;
  public int Id{get;set;}
  public string Code{get;set;}
  Order order;
  public virtual Order Order { get; set; }
  ....   
}

每个订单可以从一个或零报价，并且每个报价可能会导致订单，所以我有一个或一个一个或零关系，我如何在流动的API中首先在EF代码中实现这一点？

each Order may made from one or zero quotation, and each quotation may cause an order, so I have an "one or zero" to "one or zero" relation, how can I implement this, in EF Code first by fluent API?

推荐答案

通过将pocos更改为：

By changing pocos to:

public class Order
{
    public int OrderId { get; set; }
    public virtual Quotation Quotation { get; set; }
}
public class Quotation
{
    public int QuotationId { get; set; }
    public virtual Order Order { get; set; }
}

并使用这些映射文件：

public class OrderMap : EntityTypeConfiguration<Order>
{
    public OrderMap()
    {
        this.HasOptional(x => x.Quotation)
            .WithOptionalPrincipal()
            .Map(x => x.MapKey("OrderId"));
    }
}

public class QuotationMap : EntityTypeConfiguration<Quotation>
{
    public QuotationMap()
    {
        this.HasOptional(x => x.Order)
            .WithOptionalPrincipal()
            .Map(x => x.MapKey("QuotationId"));
    }
}

我们将有这个DB（这意味着0 .. 1-0..1）：

we will have this DB(that means 0..1-0..1):

特别感谢（ Vahid Nasiri先生）

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