Question

我正在使用SQLite-Net PCL和SQLite-Net扩展来开发使用Xamarin的应用程序。

在我的模型中，我有两个实体，我们称之为产品和卖方，它们通过多对多关系连接起来。例如，产品可以由许多卖家出售，每个卖家销售许多产品。

我是否需要创建另一个模型来建立这种关系？ ProductId是产品的主键，也是卖家的外键。

以下是我的模型：

public class Product
{
    public event PropertyChangedEventHandler PropertyChanged;

    [PrimaryKey, AutoIncrement]
    public int ProductID { get; set; }

    [MaxLength(255)]
    public string ProductName { get; set; }

    public float Price { get; set; }

    [MaxLength(255)]
    public string Brand { get; set; }

    public string category { get; set; }

    public string ImageUrl { get; set; }

    public string description { get; set; }

    private void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}



public class Retailer
{
    [PrimaryKey, AutoIncrement]
    public int RetailerID { get; set; }

    public string RetailerName { get; set; }

    public string RetailerAddress { get; set; }

    public string LogoUrl { get; set; }
}

Answer 1

您可以使用sqlite-net-extensions，它具有看起来非常适合您需求的ManyToMany属性。

public class Product
{
    public event PropertyChangedEventHandler PropertyChanged;

    [PrimaryKey, AutoIncrement]
    public int ProductID { get; set; }

    [MaxLength(255)]
    public string ProductName { get; set; }

    public float Price { get; set; }

    [MaxLength(255)]
    public string Brand { get; set; }

    public string category { get; set; }

    public string ImageUrl { get; set; }

    public string description { get; set; }

    private void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    // You should add ProductsRetailers class
    [ManyToMany(typeof(ProductsRetailers))]
    public List<Retailer> Retailers { get; set; }

}



public class Retailer
{
    [PrimaryKey, AutoIncrement]
    public int RetailerID { get; set; }

    public string RetailerName { get; set; }

    public string RetailerAddress { get; set; }

    public string LogoUrl { get; set; }

    // You should add ProductsRetailers class
    [ManyToMany(typeof(ProductsRetailers))]
    public List<Product> Products { get; set; } 
}

此外，您必须添加类似ProductsRetailers的类

public class ProductsRetailers
{
    [ForeignKey(typeof(Product))]
    public int ProductID { get; set; }

    [ForeignKey(typeof(Retailer))]
    public int RetailerID { get; set; }
}

SQLite-Net扩展两个实体之间的多对多关系

1 个答案: