由网友(坐观雾漫长安)分享简介：我工作的实体框架4.1，并使用数据注释外键。我想知道我们如何能够定义一个产品和类别之间一对多的关系。我要地图类别。的categoryId与product.cid I am working on Entity Framework 4.1 and using data annotations for foreign ke...

我工作的实体框架4.1，并使用数据注释外键。我想知道我们如何能够定义一个产品和类别之间一对多的关系。我要地图类别。的categoryId与product.cid

I am working on Entity Framework 4.1 and using data annotations for foreign keys. I want to know how can we define one to many relationship between product and categories. I want to map category. categoryId with product.cid

public class Category
{
    public string CategoryId { get; set; }
    public string Name { get; set; }

    public virtual ICollection<Product> Products { get; set; }
}

public class Product
{
    public int ProductId { get; set; }
    public string Name { get; set; }
    public string CId { get; set; }

    public virtual Category Category { get; set; }
} 

请提示

推荐答案

这两种方法应该工作：

public class Product
{
    public int ProductId { get; set; }
    public string Name { get; set; }
    [ForeignKey("Category")]
    public string CId { get; set; }

    public virtual Category Category { get; set; }
}

或者

public class Product
{
    public int ProductId { get; set; }
    public string Name { get; set; }
    public string CId { get; set; }

    [ForeignKey("CId")]
    public virtual Category Category { get; set; }
} 

ForeignKeyAttribute 用来配对导航属性和外键的属性。它包含了相关的导航属性的名称或相关的外键属性的名称。

ForeignKeyAttribute is used to pair navigation property and foreign key property. It contains either the name of related navigation property or the name of related foreign key property.