c# - Iridium ORM - 无法创建关系。 (

Question

我正在开发 Xamarin 应用程序作为学习练习，但我终生无法正确映射关系/按预期工作。 Iridium 一直是我选择的 ORM，因为它据说比标准 SQLite 更好地支持关系和自定义类型。我创建了一个单独的控制台应用程序来尝试对此进行调试，但再次遇到了麻烦。任何人都可以帮助指出我所缺少的吗？还是 Iridium/relationships/Types 或 ORM 有什么基本的我忽略了？

NuGet: iridium.db.sqlite

class Model
{
    [Column.PrimaryKey(AutoIncrement = true)]
    private int _ID;
    public int ID { get { return _ID; } set { _ID = value; } }

    [Column.Null]
    public string Name { get; set; }

    private List<ChildModel> _object;
    [Relation.OneToMany]
    private IEnumerable<ChildModel> _Objects
    {
        get { return _object; }
        set  { _object = value.ToList(); }
    }
    public List<ChildModel> Objects
    {
        get { return _object; }
        set { _object = value; }
    }

    public Model()
    {
        _object = new List<ChildModel>();
    }

}


class ChildModel
{
    [Column.PrimaryKey(AutoIncrement = true)]
    private int _ID;
    public int ID { get { return _ID; } set { _ID = value; } }

    [Column.Null]
    public string Name { get; set; }


    public ChildModel()
    {

    }
}



class Program
{
    static void Main(string[] args)
    {
        var dbContext = new StorageContext(new SqliteDataProvider("mydbTest.sqlite"));

        // Create tables (if they don't exist) yet
        dbContext.CreateTable<Model>();
        dbContext.CreateTable<ChildModel>();

        //generate test data
        Model model = new Model {Name ="Test" };
        model.Objects.Add(new ChildModel { Name = "first" });
        model.Objects.Add(new ChildModel { Name = "second" });
        model.Objects.Add(new ChildModel { Name = "third" });

        //Save Test Data in DB.
        dbContext.Insert(model, obj => obj.Objects);


        //TODO: read test data once we know it stores properly...
    }
}

Answer 1

您的模型类应该简单得多。此外，ChildModel 需要一个指向父模型的外键:

class Model
{
    [Column.PrimaryKey(AutoIncrement = true)]
    public int ID { get;set; }

    [Column.Null]
    public string Name { get; set; }

    [Relation.OneToMany(ForeignKey="ParentID")    
    public List<ChildModel> Objects {get;set;} = new List<ChildModel>();
}

class ChildModel
{
    [Column.PrimaryKey(AutoIncrement = true)]
    public int ID { get;set; }

    public int ParentID {get;set;}

    [Column.Null]
    public string Name { get; set; }
}