代码优先：无法创建一对多关系。创建0 ... 1到很多

Question

客户

public class Customer
{
    public Customer()
    {
        Addresses = new List<Address>();
        Reviews = new List<Review>();
        Products = new List<Product>();
    }
    [Key]
    public string Email { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Password { get; set; }
    public Address DefaultAddress { get; set; }
    public int DefaultAddressId { get; set; }
    public List<Address> Addresses { get; set; }
    public List<Review> Reviews { get; set; }
    public List<Product> Products { get; set; }
}

产品

public class Product
{
    public Product()
    {
        Reviews = new List < Review >();
    }

    public int Id { get; set; }
    public Category Category { get; set; }
    public string Name { get; set; }  
    public string Description { get; set; }
    public string Specification { get; set; }
    public List<Review> Reviews { get; set; }
    public List<Customer> Customers { get; set; }
}

评论

public class Review
{
    public int Id { get; set; }
    public string Text { get; set; }
    public int Stars { get; set; }
    [Required] 
    public int ProductId { get; set; }
    [Required]
    public string CustomerId { get; set; }
}

}

生成的模型

我希望“评论”与“客户”之间的关系为1对多而不是0..1对多。每个评论必须属于一个客户。我不了解如何针对“评论-产品”而不是针对客户正确映射关系。

Answer 1

我只使用了Customer和Review模型，因为那是您一次想要的答案。 以下是您的模型类别。

public class Customer
{
    public Customer()
    {
        Reviews = new HashSet<Review>();
    }

    [Key]
    public string Email { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Password { get; set; }

    public ICollection<Review> Reviews { get; set; }

}

public class Review
{
    public int Id { get; set; }
    public string Text { get; set; }
    public int Stars { get; set; }
    [Required]
    public int ProductId { get; set; }
    [Required]
    public string CustomerId { get; set; }

    [ForeignKey("CustomerId")]
    public Customer Customer { get; set; }
}

通过这种方式，您可以让客户查看评论集并将其投射到列表中。在linq查询中使用Include()方法来延迟加载客户评论集。 例如：

var customer = dbContext.Customer.Include("Reviews").where(x => x.Email == "john@gmail.com").FirstOrDefault();