與SQLite.Net.Async擴展PCL 1.3.0在同一對象上的多個@OneToOne？

Question

在使用SQLite.Net.Async擴展PCL 1.3.0的實體中是否可以有多個OneToOne關係？

例子：

[Table("body")] 
public class Body 
{ 
    [OneToOne(CascadeOperations = CascadeOperation.All)] 
    [Column ("left")] 
    public Hand Left { get; set; } 

    [OneToOne(CascadeOperations = CascadeOperation.All)] 
    [Column ("right")] 
    public Hand Right { get; set; } 
} 

[Table("hand")] 
public class Hand 
{ 
    // In this I do not need a reference back to Body. 
} 

我已經使用了以下的答案嘗試：

SQLite-Net Extension both one-to-one and one-to-many relationships between two entities

並與這些站點作爲靈感也：

https://bitbucket.org/twincoders/sqlite-net-extensions/overview

https://bitbucket.org/twincoders/sqlite-net-extensions/src/65a1f8519347c40c948855cfc1a1d4d8bbcc8748/Tests/ReflectionExtensionsTests.cs?at=master&fileviewer=file-view-default

不幸的是，目前還沒有運氣。它甚至有可能嗎？

Answer 1

是的，這是完全可能的，不幸的是，您不能依靠自動外鍵和反向關係發現，所以您需要手動指定它。

例如，對於一個int主鍵和外鍵聲明如在同一個班級：

public class Body 
{ 
    [OneToOne(foreignKey: "LeftId", CascadeOperations = CascadeOperation.All)] 
    public Hand Left { get; set; } 

    [OneToOne(foreignKey: "RightId", CascadeOperations = CascadeOperation.All)] 
    public Hand Right { get; set; } 

    // Foreign key for Left.Id 
    public int LeftId { get; set; } 
    // Foreign key for Right.Id 
    public int RightId { get; set; } 
} 

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

如果你的外鍵在Hand對象聲明的屬性的屬性是相同的：

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

    [OneToOne(foreignKey: "LeftId", CascadeOperations = CascadeOperation.All)] 
    public Hand Left { get; set; } 

    [OneToOne(foreignKey: "RightId", CascadeOperations = CascadeOperation.All)] 
    public Hand Right { get; set; } 
} 

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

    // Foreign key for Body.Id where this object is Left 
    public int LeftId { get; set; } 
    // Foreign key for Body.Id where this object is Right 
    public int RightId { get; set; } 
} 

如果需要，反相屬性必須在OneToOne屬性的兩端的inverseProperty鍵中指定：

public class Body 
{ 
    // Skipping foreign keys and primary key 

    [OneToOne(foreignKey: "LeftId", inverseProperty: "LeftBody", CascadeOperations = CascadeOperation.All)] 
    public Hand Left { get; set; } 

    [OneToOne(foreignKey: "RightId", inverseProperty: "RightBody", CascadeOperations = CascadeOperation.All)] 
    public Hand Right { get; set; } 
} 

public class Hand 
{ 
    // Skipping foreign keys and primary key 

    [OneToOne(foreignKey: "LeftId", inverseProperty: "Left", CascadeOperations = CascadeOperation.All)] 
    public Body LeftBody { get; set; } 

    [OneToOne(foreignKey: "RightId", inverseProperty: "Right", CascadeOperations = CascadeOperation.All)] 
    public Body RightBody { get; set; } 
}