我有两个简单的表格如下:
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:
公开名单&lt; MediaPartner&gt; IdMediaPartner {get;组; }
或
public MediaPartner IdMediaPartner {get;组; }
不编译。
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!
答案 0 :(得分:6)
SQLite-net仅使用索引提供跨表引用,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; }
}
至少有一个sqlite-net扩展允许声明OneToMany
属性 - 请参阅https://bitbucket.org/twincoders/sqlite-net-extensions,其中包含以下代码:
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mvvmcross插件支持,是跨平台的,可用于分叉和贡献。