孤儿仍然在数据库中，即使orphanRemoval = true在一对多关系（JPA / Hibernate）

问题描述

  
 c> orphanRemoval = true 与一个单向一对多关联没有任何问题。
 
 
 
实际上，我测试了您的代码和以下内容方案（ AbstractPolicyRule 正确地）执行等于 /  hashCode  / p> 
 
 
  Category category = new Category（）; 
 AbstractPolicyRule policyRule1 = new AbstractPolicyRule（foo）; 
 
 category.addToActivePolicyRules（policyRule1）; 
 em.persist（category）; 
 em.flush（）; 
 
 assertNotNull（category.getId（））; 
 assertNotNull（category.getActivePolicyRules（））; 
 assertEquals（1，category.getActivePolicyRules（）。size（））; 
 
 category.removeFromActivePolicyRules（policyRule1）; 
 category.addToActivePolicyRules（new AbstractPolicyRule（bar））; 
 // category = em.merge（category）; //可以使用或不使用
 em.flush（）; 
 assertEquals（1，category.getActivePolicyRules（）。size（））; 
  
正常工作。在生成的跟踪下面： 
 
 
 
 22：54：30.817 [main] DEBUG org.hibernate.SQL  - 插入类别（id，category_name）值（空，？）
 Hibernate：插入类（id，category_name）值（空，？）
 22：54：30.824 [main] TRACE org.hibernate.type.StringType  - 参数：1 
 22：54：30.844 [main] DEBUG ohid.IdentifierGeneratorHelper  - 本地生成的标识：1 
 ... 
 22：54：30.872 [main] DEBUG org.hibernate。 SQL插入AbstractPolicyRule（id，name）values（null，？）
 Hibernate：插入AbstractPolicyRule（id，name）values（null，？）
 22：54：30.873 [main] TRACE org .hibernate.type.StringType  - 将'foo'绑定到参数：1 
 22：54：30.874 [main] DEBUG ohid.IdentifierGeneratorHelper  - 本地生成的标识：1 
 ... 
 22 ：54：30.924 [main] DEBUG org.hibernate.SQL  -  update AbstractPolicyRule set category_policy_id =？其中id =？ 
 Hibernate：更新AbstractPolicyRule set category_policy_id =？其中id =？ 
 22：54：30.927 [main] TRACE org.hibernate.type.LongType  - 绑定'1'参数：1 
 22：54：30.928 [main] TRACE org.hibernate.type.LongType  - 绑定'1'到参数：2 
 22：54：30.929 [main] DEBUG ohpcAbstractCollectionPersister  - 完成插入集合：插入1行
 22：54：30.929 [main] DEBUG org.hibernate.jdbc。 AbstractBatcher  - 执行批量大小：1 
 ... 
 22：54：30.945 [main] DEBUG org.hibernate.SQL  - 插入AbstractPolicyRule（id，name）values（null，？）
 Hibernate：插入到AbstractPolicyRule（id，name）values（null，？）
 22：54：30.948 [main] TRACE org.hibernate.type.StringType  - 绑定bar到参数：1 
 22：54：30.948 [main] DEBUG org.hibernate.SQL  - 更新AbstractPolicyRule set category_policy_id =更新AbstractPolicyRule set_type_policy_id = null where category_policy_id =？和id =？ 
 Hibernate：update AbstractPolicyRule set category_policy_id = null where category_policy_id =？和id =？ 
 22：54：30.991 [main] TRACE org.hibernate.type.LongType  - 将参数绑定为'1'：1 
 22：54：30.992 [main] TRACE org.hibernate.type.LongType  - 绑定'1'参数：2 
 22：54：30.993 [main] DEBUG ohpcAbstractCollectionPersister  - 完成删除集合行：1删除
 22：54：30.993 [main] DEBUG ohpcAbstractCollectionPersister  - 插入集合：[com.stackoverflow.q3304092.Category.activePolicyRules＃1] 
 22：54：30.994 [main] DEBUG org.hibernate.jdbc.AbstractBatcher  - 执行批处理大小：1 
 ... 
 22：54：30.996 [main] DEBUG org.hibernate.SQL  -  update AbstractPolicyRule set category_policy_id =？其中id =？ 
 Hibernate：更新AbstractPolicyRule set category_policy_id =？其中id =？ 
 22：54：30.997 [main] TRACE org.hibernate.type.LongType  - 绑定参数为'1'：1 
 22：54：30.998 [main] TRACE org.hibernate.type.LongType  - 绑定'2'到参数：2 
 22：54：31.002 [main] DEBUG ohpcAbstractCollectionPersister  - 完成插入行：1插入
 ... 
 22：54：31.015 [main] DEBUG org.hibernate.SQL  - 从AbstractPolicyRule中删除，其中id =？ 
 Hibernate：从AbstractPolicyRule中删除，其中id =？ 
 22：54：31.017 [main] TRACE org.hibernate.type.LongType  - 将参数绑定为'1'：1 
 
第一条政策规则被删除。
 
 
 
如果这并不代表您在做什么，那么您应该提供更多代码。
 
 
 
 更新：回答OP的评论... 
只是一个猜测：因为 orphanRemoval 是一个JPA的东西，我不知道是否 saveOrUpdate 会适当地处理它（实际上，我以为你使用 EntityManager  API，因为你提到过JPA）。
 
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@Table(name = "company_policies")
@DiscriminatorColumn(name = "rule_name")
public abstract class AbstractPolicyRule implements Serializable {

  @Transient
  private static final long serialVersionUID = 1L;

  @Id
  @GeneratedValue
  private Long id;
  private String value;

  ...
}
_
@Entity
public class Category implements Serializable {

  @Transient
  private static final long serialVersionUID = 1L;

  @Id
  @GeneratedValue
  private Long id;
  @Column(name = "category_name")
  private String name;

  @OneToMany(fetch = FetchType.EAGER, cascade = { CascadeType.ALL }, orphanRemoval = true)
  @JoinColumn(name = "category_policy_id", referencedColumnName = "id")
  private Set<AbstractPolicyRule> activePolicyRules;

  ...
}
When this Set is updated the existing activePolicyRules have their category_policy_id set to null in the database and new ones are inserted.  I'd like for the original ones to be deleted.  
I thought adding the orphanRemoval = true would do that but it's not.  Other questions I've seen on this appear to have bi-directional relationships and setting the parent to null solves it, but this is not a bi-directional relationship.
Any suggestions?
Using Hibernate 3.5.3
Edit:This only happens when an existing AbstractPolicyRule exists in the database, I remove it from the list and then save the Category again.  It's foreign key, category_policy_id, is set to null instead of being deleted.
[DEBUG] Collection found: [domain.category.Category.activePolicyRules#1], was: 
[<unreferenced>] (initialized)
[DEBUG] Flushed: 0 insertions, 2 updates, 0 deletions to 2 objects
[DEBUG] Flushed: 1 (re)creations, 0 updates, 1 removals to 1 collections
...
[DEBUG] Deleting collection: [domain.category.Category2.activePolicyRules#1]
[DEBUG] about to open PreparedStatement (open PreparedStatements: 0, globally: 0)
[DEBUG] update company_policies set category_policy_id=null where category_policy_id=?
[DEBUG] done deleting collection
Also tried a join table since the Hibernate documentation discourages the previous way:
@Entity
public class Category implements Serializable {

  @Transient
  private static final long serialVersionUID = 1L;

  @Id
  @GeneratedValue
  private Long id;
  @Column(name = "category_name")
  private String name;

  @OneToMany(fetch = FetchType.EAGER, cascade = { CascadeType.ALL }, orphanRemoval = true)
  @JoinTable(name = "policy_rule_mapping", 
    joinColumns = @JoinColumn(name = "category_id"), 
    inverseJoinColumns = @JoinColumn(name = "rule_id"))
  private Set<AbstractPolicyRule> activePolicyRules;

  ...
}
This has the same issue.  The row in the mapping table is deleted but the AbstractPolicyRule still contains the removed item.
 解决方案 
I'm using orphanRemoval=true with an unidirectional One-to-Many association without any problem.
And actually, I tested your code and the following scenario (AbstractPolicyRule implementing equals/hashCode correctly):
Category category = new Category();
AbstractPolicyRule policyRule1 = new AbstractPolicyRule("foo");

category.addToActivePolicyRules(policyRule1);
em.persist(category);
em.flush();

assertNotNull(category.getId());
assertNotNull(category.getActivePolicyRules());
assertEquals(1, category.getActivePolicyRules().size());

category.removeFromActivePolicyRules(policyRule1);
category.addToActivePolicyRules(new AbstractPolicyRule("bar"));
// category = em.merge(category); // works with or without
em.flush();
assertEquals(1, category.getActivePolicyRules().size());
just works as expected. Below the generated traces:
22:54:30.817 [main] DEBUG org.hibernate.SQL - insert into Category (id, category_name) values (null, ?)
Hibernate: insert into Category (id, category_name) values (null, ?)
22:54:30.824 [main] TRACE org.hibernate.type.StringType - binding null to parameter: 1
22:54:30.844 [main] DEBUG o.h.id.IdentifierGeneratorHelper - Natively generated identity: 1
...
22:54:30.872 [main] DEBUG org.hibernate.SQL - insert into AbstractPolicyRule (id, name) values (null, ?)
Hibernate: insert into AbstractPolicyRule (id, name) values (null, ?)
22:54:30.873 [main] TRACE org.hibernate.type.StringType - binding 'foo' to parameter: 1
22:54:30.874 [main] DEBUG o.h.id.IdentifierGeneratorHelper - Natively generated identity: 1
...
22:54:30.924 [main] DEBUG org.hibernate.SQL - update AbstractPolicyRule set category_policy_id=? where id=?
Hibernate: update AbstractPolicyRule set category_policy_id=? where id=?
22:54:30.927 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 1
22:54:30.928 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 2
22:54:30.929 [main] DEBUG o.h.p.c.AbstractCollectionPersister - done inserting collection: 1 rows inserted
22:54:30.929 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - Executing batch size: 1
...
22:54:30.945 [main] DEBUG org.hibernate.SQL - insert into AbstractPolicyRule (id, name) values (null, ?)
Hibernate: insert into AbstractPolicyRule (id, name) values (null, ?)
22:54:30.948 [main] TRACE org.hibernate.type.StringType - binding 'bar' to parameter: 1
22:54:30.948 [main] DEBUG o.h.id.IdentifierGeneratorHelper - Natively generated identity: 2
...
22:54:30.990 [main] DEBUG org.hibernate.SQL - update AbstractPolicyRule set category_policy_id=null where category_policy_id=? and id=?
Hibernate: update AbstractPolicyRule set category_policy_id=null where category_policy_id=? and id=?
22:54:30.991 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 1
22:54:30.992 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 2
22:54:30.993 [main] DEBUG o.h.p.c.AbstractCollectionPersister - done deleting collection rows: 1 deleted
22:54:30.993 [main] DEBUG o.h.p.c.AbstractCollectionPersister - Inserting rows of collection: [com.stackoverflow.q3304092.Category.activePolicyRules#1]
22:54:30.994 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - Executing batch size: 1
...
22:54:30.996 [main] DEBUG org.hibernate.SQL - update AbstractPolicyRule set category_policy_id=? where id=?
Hibernate: update AbstractPolicyRule set category_policy_id=? where id=?
22:54:30.997 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 1
22:54:30.998 [main] TRACE org.hibernate.type.LongType - binding '2' to parameter: 2
22:54:31.002 [main] DEBUG o.h.p.c.AbstractCollectionPersister - done inserting rows: 1 inserted
...
22:54:31.015 [main] DEBUG org.hibernate.SQL - delete from AbstractPolicyRule where id=?
Hibernate: delete from AbstractPolicyRule where id=?
22:54:31.017 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 1
The first policy rule gets deleted.
If this is not representative of what you're doing, you should maybe provide more code.
Update: Answering a comment from the OP...
Just a guess: since orphanRemoval is a JPA thing, I wonder if saveOrUpdate will deal appropriately with it (actually, I thought you were using the EntityManager API since you mentioned JPA).
                        
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