SQLite 扩展异常：ManyToOne 关系目标必须具有主键

Question

您可以看到标题中的错误。还有我的table类:

public class Cars : Table
{
    [NotNull]
    public string name { get; set; }
    [ForeignKey(typeof(Models)), NotNull]
    public int model_out_id { get; set; }
    [ForeignKey(typeof(Bodies)), NotNull]
    public int body_out_id { get; set; }
    [MaxLength(50)]
    public string vin { get; set; }
    [MaxLength(4), NotNull]
    public int year { get; set; }
    [Indexed, NotNull]
    public long created_at { get; set; } = DateTime.Now.GetTimestamp();

    [ManyToOne(CascadeOperations = CascadeOperation.CascadeRead)]
    public Models Model { get; set; }
    [ManyToOne(CascadeOperations = CascadeOperation.CascadeRead)]
    public Bodies Body { get; set; }

    [OneToMany]
    public List<CarGlasses> CarGlasses { get; set; }

    public Cars()
    {
    }
}

public class Models : TableLibrary
{
    [PrimaryKey, NotNull]
    public int out_id { get; set; }
    [NotNull]
    public string name { get; set; }
    [ForeignKey(typeof(Marks)), NotNull]
    public int mark_out_id { get; set; }
    [Indexed, NotNull]
    public int year_from { get; set; }
    [Indexed]
    public int? year_to { get; set; }

    [ManyToOne(CascadeOperations = CascadeOperation.CascadeRead), Ignore]
    public Marks Mark { get; set; }

    public Models()
    {
    }
}

此处出现错误：

inst.GetChild(car, "Model");

inst 是 SQLite.Net.SQLiteConnection 实例

当我将库作为纯代码使用时一切正常，但现在我将其添加为 PCL 参考。如您所见，PrimaryKey 存在于 Models table 中。这段代码有什么问题？

Answer 1

这是我在 xamarin 论坛上的帖子。我有解决办法。

https://forums.xamarin.com/discussion/comment/288455

SQLite 扩展异常：ManyToOne 关系目标必须具有主键

SQLite Extensions exception: ManyToOne relationship destination must have Primary Key

sqlite

android

xamarin

sqlite-net

sqlite-net-extensions