Hibernate 复合注释

Question

我是 Hibernate 的新手，正在尝试将连接表中的额外列映射到父类。我可以在 http://docs.jboss 找到一个示例.org/hibernate/core/3.5/reference/en/html/components.html

<class name="eg.Order" .... >
....
<set name="purchasedItems" table="purchase_items" lazy="true">
<key column="order_id">
<composite-element class="eg.Purchase">
<property name="purchaseDate"/>
<property name="price"/>
<property name="quantity"/>
<many-to-one name="item" class="eg.Item"/> <!-- class attribute is optional -->
</composite-element>
</set>
</class>

我想要纯注释中的上述 xml 示例。任何帮助将不胜感激。

谢谢

Answer 1

采购类别：

package eg;

@javax.persistence.Embeddable
public class Purchase{

    private Date purchaseDate;
    private Double price;
    private Integer quantity;

    @javax.persistence.ManyToOne
    private Item item;

    // getters and setters
}

订购类别：

package eg;

@javax.persistence.Entity
public class Order {

    @javax.persistence.ElementCollection(fetch = javax.persistence.FetchType.LAZY)
    @javax.persistence.CollectionTable( 
         name = "purchase_items", 
         joinColumns = @JoinColumn( name = "order_id" ) 
    )
    java.util.Set<eg.Purchase> purchasedItems;

    // getter and setter for purchasedItems
}

Answer 2

请参阅http://docs.jboss.org /hibernate/core/3.6/reference/en-US/html_single/#collections-ofvalues。从 3.6、IIRC 开始，注释就成为 hibernate 核心的一部分，因此注释的文档被嵌入到 3.6 的核心文档中。对于以前的版本，它是单独记录的（请参阅 http:// docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#d0e1821）