JPA 2/Hibernate orphan删除仍然无法与@OneToMany一起使用？

Question

我正在尝试在Hibernate 4.3.5/JPA2对象中使用orphanRemoval,但它似乎没有像我预期的那样工作.但是,如果我做错了什么,或者这仍然是Hibernate中的错误,我不确定.

鉴于以下关系(为了简洁省略了@Version,getters和setter):

@Entity
public class Provider implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    private String name;

    @OneToMany(orphanRemoval=true,cascade=CascadeType.REMOVE)
    @JoinColumn(name="provider_id", referencedColumnName="id")
    private List<Contract> contracts;
}


@Entity
public class Contract implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    private String volume;

    @OneToMany(orphanRemoval=true,cascade=CascadeType.REMOVE) // delete any attachments that were previously uploaded with this contract
    @JoinTable(name="contract_attachment", joinColumns = @JoinColumn(name = "contract_id", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "attachment_id", referencedColumnName = "id"))
    private List<Attachment> attachments;
}

@Entity
public class Attachment implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    private String filename;
}

我希望如果我从Provider.contracts列表中删除一个合同,它将删除合同表中的相应行以及附件表中的所有相关附件.但是,只有合同表被删除.附件表未被修改.

例如:

    // loop over all contracts and delete the one with the matching id
    for(Iterator<Contract> it = provider.getContracts().iterator(); it.hasNext();){
        Contract c = it.next();
        if( c.getId() == contractId ){
            it.remove();
            break;
        }
    }

鉴于附件是相对于合同表的ManyToOne,如果删除了合同,则附件是孤立的.但即使使用orphanRemoval=true,这也不会删除数据库中的行.

我发现了几个与Hibernate 3相关的问题(这里都是SO,Jira和其他地方的在线),但我已经明白它已经在Hibernate 4中修复了.但是使用Hibernate 4.3.5我仍然看到这个问题.从这个问题来看,它似乎有效,所以我不确定为什么我无法使其正常运行.

我的代码中是否存在错误/缺失,或者Hibernate仍存在问题？我是否需要实施equals并hashCode在任何这些实体类中orphanRemoval正常工作？我尝试在Contract和Attachment中实现这两种方法,但没有任何区别.

查看Hibernate日志,它显示Hibernate对连接表(或FK映射)进行更改,但实际上并未从关联表中删除该行.我可以在Contract表中看到Hibernate设置provider_id = null,但不应该删除Contract行吗？

2014-07-04 15:06:41,333 [main] [-] DEBUG org.hibernate.SQL - 
    /* update
        com.ia.domain.Provider */ update
            provider 
        set
            default_contact_id=?,
            name=?,
            type=?,
            version=?,
            website=? 
        where
            id=? 
            and version=?
Hibernate: 
    /* update
        com.ia.domain.Provider */ update
            provider 
        set
            default_contact_id=?,
            name=?,
            type=?,
            version=?,
            website=? 
        where
            id=? 
            and version=?
2014-07-04 15:06:41,334 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [1] as [BIGINT] - [null]
2014-07-04 15:06:41,334 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [name_3]
2014-07-04 15:06:41,335 [main] [-] TRACE org.hibernate.type.EnumType - Binding [CARRIER] to parameter: [3]
2014-07-04 15:06:41,336 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [4] as [INTEGER] - [2]
2014-07-04 15:06:41,336 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [5] as [VARCHAR] - [website_3]
2014-07-04 15:06:41,337 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [6] as [BIGINT] - [4]
2014-07-04 15:06:41,338 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [7] as [INTEGER] - [1]
2014-07-04 15:06:41,342 [main] [-] DEBUG org.hibernate.SQL - 
    /* delete one-to-many com.ia.domain.Provider.contracts */ update
            contract 
        set
            provider_id=null 
        where
            provider_id=?
Hibernate: 
    /* delete one-to-many com.ia.domain.Provider.contracts */ update
            contract 
        set
            provider_id=null 
        where
            provider_id=?
2014-07-04 15:06:41,344 [main] [-] TRACE hibernate.type.descriptor.sql.BasicBinder - binding parameter [1] as [BIGINT] - [4]

Answer 1

老实说,我不知道为什么,但如果你在实体中添加CascadeType.PERSIST(或更好CascadeType.ALL)你的@OneToMany关系,Provider它将按预期工作.

可能Hibernate文档缺少这个小细节.

使用JPA2 更新 EclipseLink 2.5.1似乎没有此问题

第二次更新

在第2.9节"实体关系"中,JPA 2.1规范说:"如果孤立的实体是分离的,新的或已删除的实体,则orphanRemoval的语义不适用."

我不知道你的相关实体是否已经分离,但如果是,那么这不是一个bug :)