实体框架多柱由流畅API主键 [英] Entity Framework Multiple Column as Primary Key by Fluent Api

问题描述

以上是我简单的领域类。的

These are my simplified domain classes.

public class ProductCategory
{
    public int ProductId { get; set; }
    public int CategoryId { get; set; }

    public virtual Product Product { get; set; }
    public virtual Category Category { get; set; }
}

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
} 

public class Category
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int? ParentCategoryId { get; set;} 
} 

这是我的映射类。但它不工作。的

This is my mapping class. But it doesnt work.

public class ProductCategoryMap : EntityTypeConfiguration<ProductCategory>
{
    public ProductCategoryMap()
    {
        ToTable("ProductCategory");
        HasKey(pc => pc.ProductId);
        HasKey(pc => pc.CategoryId);
    }
}

我应该如何映射这些类来提供，这样一个产品可以在多个类别中可以看出？的

How should I map these classes to provide, so that one product can be seen in multiple categories ?

推荐答案

使用匿名类型的对象，而不是2个独立的语句：

Use anonymous type object instead of 2 separated statements:

    HasKey(pc => new { pc.ProductId, pc.CategoryId});

从MSDN：<一href="http://msdn.microsoft.com/en-us/library/gg671266%28v=vs.103%29.aspx">EntityTypeConfiguration.HasKey方法

如果主键是由多个性能高达然后指定一个匿名类型包括属性。例如，在C＃ T =＆GT;新{t.Id1，t.Id2} 并在Visual Basic .NET 函数（t）的新从{t.Id1，t.Id2} 。

If the primary key is made up of multiple properties then specify an anonymous type including the properties. For example, in C# t => new { t.Id1, t.Id2 } and in Visual Basic .Net Function(t) New From { t.Id1, t.Id2 }.

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