sqlite - MVVMCross Community Sqlite - 表之间的关系

Question

我有两个简单的表如下:

public class MediaPartner
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    public string PhoneNumber { get; set; }
    public string CompanyName { get; set; }
    public double Lat { get; set; }
    public double Lng { get; set; }
    public DateTime InsertedUtc { get; set; }
}    

public class ImageGroup
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    public List<MediaPartner> IdMediaPartner { get; set; }
    public string ImagePath { get; set; }
    public bool IsSent { get; set; }
    public DateTime InsertedUtc { get; set; }
}

问题:

public List< MediaPartner > IdMediaPartner { get; set; }
OR
public MediaPartner IdMediaPartner { get; set; }
does not compile.

我的问题是:有没有办法在这两个表之间建立一对多的关系？

谢谢!

Answer 1

SQLite-net 仅提供使用索引的跨表引用，例如:

public class Stock
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    [MaxLength(8)]
    public string Symbol { get; set; }
}

public class Valuation
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    [Indexed]
    public int StockId { get; set; }
    public DateTime Time { get; set; }
    public decimal Price { get; set; }
}

sqlite-net 至少有一个扩展允许 OneToMany要声明的属性 - 参见 https://bitbucket.org/twincoders/sqlite-net-extensions这使代码如下:

public class Stock
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    [MaxLength(8)]
    public string Symbol { get; set; }

    [OneToMany]      // One to many relationship with Valuation
    public List<Valuation> Valuations { get; set; }
}

public class Valuation
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }

    [ForeignKey(typeof(Stock))]     // Specify the foreign key
    public int StockId { get; set; }
    public DateTime Time { get; set; }
    public decimal Price { get; set; }

    [ManyToOne]      // Many to one relationship with Stock
    public Stock Stock { get; set; }
}

我不确定这个的确切实现 - 例如我不知道这是否使用真正的 FOREIGN KEY约束 - 但代码是开源的，正在积极开发中，内置了 mvvmcross 插件支持，是跨平台的，可用于 fork 和贡献。