流畅的 NHibernate 将来自接口的属性映射到一处

Question

如果许多类实现相同的接口，是否可以将这些接口属性映射到一处？还有更多代码@ pastebin

你可以在这里看到类有一些公共接口（但不是全部都是公共基类）我不得不重复映射。

public class PostMapping : SubclassMap<Post>
{
    public PostMapping()
    {
        Map(x => x.Text, "Text");
        // coming from IMultiCategorizedPage
        HasManyToMany(x => x.Categories).Table("PageCategories").ParentKeyColumn("PageId").ChildKeyColumn("CategoryId").Cascade.SaveUpdate();
        // coming from IMultiTaggedPage
        HasManyToMany(x => x.Tags).Table("PageTags").ParentKeyColumn("PageId").ChildKeyColumn("TagId").Cascade.SaveUpdate();
        // coming from ISearchablePage
        Map(x => ((ISearchablePage)x).SearchIndex, "SearchIndex").LazyLoad();
    }
}
public class ArticleMapping : SubclassMap<Article>
{
    public ArticleMapping()
    {
        Map(x => x.Text, "Text");
        // coming from ISingleCategorizedPage
        References(x => x.Category, "CategoryId");
        // coming from IMultiTaggedPage
        HasManyToMany(x => x.Tags).Table("PageTags").ParentKeyColumn("PageId").ChildKeyColumn("TagId").Cascade.SaveUpdate();
        // coming from ISearchablePage
        Map(x => ((ISearchablePage)x).SearchIndex, "SearchIndex").LazyLoad();
    }
}

Answer 1

如果 C# 具有完整的多重继承而不仅仅是多重接口继承，那么这将很容易。看起来最接近的是为映射基类创建一个包装接口来保存公共元素。然后，您可以创建从其继承的表特定映射类。这段代码的内容大致如下：

public class BasePageMapping : SubclassMap<IPage> //IPage could inherit: IMultiTaggedPage, ISearchablePage
{
    public BasePageMapping()
    {
        Map(x => x.Text, "Text");
        // coming from IMultiTaggedPage
        HasManyToMany(x => x.Tags).Table("PageTags").ParentKeyColumn("PageId").ChildKeyColumn("TagId").Cascade.SaveUpdate();
        // coming from ISearchablePage
        Map(x => ((ISearchablePage)x).SearchIndex, "SearchIndex").LazyLoad();
    }
}

public class PostMapping : BasePageMapping
{
    public PostMapping()  // don't need to specify : base() because it happens automatically
    {
        Table("the specific table");

        HasManyToMany(x => x.Categories).Table("PageCategories").ParentKeyColumn("PageId").ChildKeyColumn("CategoryId").Cascade.SaveUpdate();

        //Other table specific mappings:
    }
}