Question

我在RestorableEnvironment和IBaselineEntity个对象之间存在一对多的关系：给定的RestorableEnvironment将只有一个IBaselineEntity个对象，但每个IBaselineEntity {1}}对象可以绑定到0-n RestorableEnvironment个对象。但是，IBaselineEntity以两种方式之一实现：通过文件或通过数据库。我的课程（通常）如下：

public interface IBaselineEntity
{
    BaselineImage BuildImage();
    //Remainder of interface
}

public class BaselineFile : IBaseline
{
    //implementation
}

public class BaselineDatabase : IBaseline
{
    //implementation
}

public class RestorableEnvironment
{
    public IBaselineEntity BaselineEntity { get; set; }
    //Remainder of class
}

NHibernate需要在references语句中具体实现IBaselineEntity。为了解决这个问题，我已将RestorableEnvironment更新为：

public class RestorableEnvironment
{
    public IBaselineEntity BaselineEntity
    {
        get { return BaselineDatabase ?? BaselineFile; }
        set
        {
            BaselineFile = value as BaselineFile;
            BaselineDatabase = value as BaselineDatabase;
        }
    }

    private BaselineFile _baselineFile;
    public BaselineFile BaselineFile
    {
        get { return _baselineFile; }
        protected set
        {
            _baselineFile = value;
            if (value != null)
                BaselineDatabase = null;
        }
    }

    private BaselineDatabase _baselineDatabase;
    public BaselineDatabase BaselineDatabase 
    {
        get { return _baselineDatabase; }
        protected set
        {
            _baselineDatabase= value;
            if (value != null)
                BaselineFile = null;
        }
    }

    // Remainder of class
}

现在我有了具体的类，我现在可以在NHibernate中映射，但这感觉就像一个黑客。有任何改进建议吗？

Answer 1

将其映射为任何参考

使用流畅的地图

// ClassMap<RestorableEnvironment>
RestorableEnvironmentMap()
{
    ReferenceAny(e => e.BaselineEntity)
        .EntityIdentifierColumn("entirtyid")
        .EntityTypeColumn("entitytype")
        .IdentityType<int>()
        .MetaType<string>()
        .AddMetaValue<E1>("e1")
        .AddMetaValue<E2>("e2");
}

NHibernate：持久引用多个Contrete类的接口

1 个答案: