Nhibernate 一对多关联
我有这样一个简单的模型：
public abstract class Entity
{
public virtual Guid Id { get; protected set; }
}
public class Post : Entity
{
public String Title { get ; set; }
public String Content { get; set; }
public DateTime Timestamp { get; set; }
public Byte[] Thumbnail { get; set; }
}
public class Blog : Entity
{
public String Title { get; set; }
public ISet<Post> Posts { get; set; }
}
然后我有这样的映射：
BLOG
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true assembly="Application.Domain" namespace="Application.Domain.Entities">
<class name="Blog">
<!-- id generator -->
<id name="Id">
<generator class="guid.comb" />
</id>
<!-- properties/columns -->
<property name="Title" not-null="true" />
<!-- components/columns -->
<!-- associations -->
<set name="Posts" cascade="all">
<!-- key column? -->
</set>
</class>
</hibernate-mapping>
POST
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" assembly="Application.Domain" namespace="Application.Domain.Entities">
<class name="Blog">
<!-- id generator -->
<id name="Id">
<generator class="guid.comb" />
</id>
<!-- properties/columns -->
<property name="Title" not-null="true" />
<property name="Content" not-null="true" />
<property name="Timestamp" not-null="true"/>
<property name="Thmbnail" />
<!-- components/columns -->
<!-- associations -->
</class>
</hibernate-mapping>
如何映射一对多关联（单向）？
谢谢！
I have such a simple model:
public abstract class Entity
{
public virtual Guid Id { get; protected set; }
}
public class Post : Entity
{
public String Title { get ; set; }
public String Content { get; set; }
public DateTime Timestamp { get; set; }
public Byte[] Thumbnail { get; set; }
}
public class Blog : Entity
{
public String Title { get; set; }
public ISet<Post> Posts { get; set; }
}
Then I have such mappings:
BLOG
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true assembly="Application.Domain" namespace="Application.Domain.Entities">
<class name="Blog">
<!-- id generator -->
<id name="Id">
<generator class="guid.comb" />
</id>
<!-- properties/columns -->
<property name="Title" not-null="true" />
<!-- components/columns -->
<!-- associations -->
<set name="Posts" cascade="all">
<!-- key column? -->
</set>
</class>
</hibernate-mapping>
POST
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" assembly="Application.Domain" namespace="Application.Domain.Entities">
<class name="Blog">
<!-- id generator -->
<id name="Id">
<generator class="guid.comb" />
</id>
<!-- properties/columns -->
<property name="Title" not-null="true" />
<property name="Content" not-null="true" />
<property name="Timestamp" not-null="true"/>
<property name="Thmbnail" />
<!-- components/columns -->
<!-- associations -->
</class>
</hibernate-mapping>
How do I map one-to-many association (unidirectional)?
Thanks!
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评论（2）
在博客映射文件中，您需要在引用帖子表中的
Blog实体的外键列之间定义一个一对多关系，假设它是BlogId并且您需要告诉他们这个一对多关系与哪个类相关，在您的情况下，这将是Post类，您需要用它的完全限定来定义它包含此类和逗号的命名空间，然后是程序集名称 下列的：In the blog mapping file you need to define a
one-to-manyrelation between the foreign key column that references theBlogentity in the post table say it isBlogIdand you need to tell'em what class this one-to-many relation relates to, in your case this will be thePostclass and you need to define it with it's fully qualified namespace that contains this class and a comma then the assembly name as following:我认为这与此处描述的问题相同。
而且，我认为您在映射 Post 类名称时犯了一个错误，不应该是 Blog。另外，在您的示例中，从帖子到博客没有关系。
I think it's the same problem as described here.
And also, I think you have a mistake in mapping of the Post - class name shouldn't be Blog. Also, there's no relation from Post to Blog in your example.