再次JoinTable未填入多对多休眠关系

Question

| AA |多对多| BB |多对多| CC |

与映射连接表成为

| AA | - | AA_BB | - | BB | - | BB_CC | - | CC |

（我不能发表图片对不起，低信誉）

编辑： 短的问题是 为什么如果创建了Aa元素，BB元素，抄送元素 添加抄送至BB收集，BB至Aa收藏 保存（Aa） 工作正常（已填充AA_BB）？

但是，如果我创建了Bb元素，AA元素，抄送元素 添加了Aa至BB收集 添加抄送至BB收集 保存（BB） （AA_BB 不填？）

BB_CC总是填充。

末编辑

CREATE TABLE BB_CC (
    BBIDBB number(10) NOT NULL, 
    CCIDCC number(10) NOT NULL, 
    PRIMARY KEY (BBIDBB, 
    CCIDCC)); 
CREATE TABLE AA_BB (
    AAIDAA number(10) NOT NULL, 
    BBIDBB number(10) NOT NULL, 
    PRIMARY KEY (AAIDAA, 
    BBIDBB)); 
CREATE TABLE CC (
    IDCC number(10) NOT NULL, 
    DESCR varchar2(10) NOT NULL, 
    PRIMARY KEY (IDCC)); 
CREATE TABLE BB (
    IDBB number(10) NOT NULL, 
    DESCR varchar2(10) NOT NULL, 
    PRIMARY KEY (IDBB)); 
CREATE TABLE AA (
    IDAA number(10) NOT NULL, 
    DESCR varchar2(10) NOT NULL, 
    PRIMARY KEY (IDAA)); 
ALTER TABLE BB_CC ADD CONSTRAINT FKBB_CC976918 FOREIGN KEY (BBIDBB) REFERENCES BB (IDBB); 
ALTER TABLE BB_CC ADD CONSTRAINT FKBB_CC529716 FOREIGN KEY (CCIDCC) REFERENCES CC (IDCC); 
ALTER TABLE AA_BB ADD CONSTRAINT FKAA_BB470776 FOREIGN KEY (AAIDAA) REFERENCES AA (IDAA); 
ALTER TABLE AA_BB ADD CONSTRAINT FKAA_BB23574 FOREIGN KEY (BBIDBB) REFERENCES BB (IDBB); 

Hibernate配置文件

<?xml version='1.0' encoding='utf-8'?> 
<!DOCTYPE hibernate-configuration PUBLIC 
     "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 
     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> 
<hibernate-configuration> 
    <session-factory> 
<!-- ORACLE --> 
     <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property> 
     <property name="connection.url">jdbc:oracle:thin:@10.10.1.8:1521:GEROS</property> 
     <property name="connection.username">xxxx</property> 
     <property name="connection.password">xxxx</property> 
     <property name="dialect">org.hibernate.dialect.OracleDialect</property> 

     <!-- JDBC connection pool (use the built-in) --> 
     <property name="connection.pool_size">1</property> 

     <!-- Disable the second-level cache --> 
     <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> 

     <!-- Echo all executed SQL to stdout --> 
     <property name="show_sql">true</property> 

     <!-- Drop and re-create the database schema on startup--> 
     <property name="hbm2ddl.auto">create</property> 

     <!-- Names the annotated entity class --> 
     <mapping class="it.erreeffe.erreeffe2.Aa"/> 
     <mapping class="it.erreeffe.erreeffe2.Bb"/> 
     <mapping class="it.erreeffe.erreeffe2.Cc"/> 
    </session-factory> 
</hibernate-configuration> 

而且从表 机管局（BB，CC类似）的某些部分缺失的逆转JPA类。

@Entity 
public class Aa implements Serializable { 
    private static final long serialVersionUID = 1L; 

    @Id 
    @SequenceGenerator(name="AA_IDAA_GENERATOR", sequenceName="SEQ_AA") 
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="AA_IDAA_GENERATOR") 
    private long idaa; 

    private String descr; 

    //bi-directional many-to-many association to Bb 
    @ManyToMany(cascade={CascadeType.ALL}) 
    @JoinTable(
     name="AA_BB" 
     , joinColumns={ 
      @JoinColumn(name="AAIDAA") 
      } 
     , inverseJoinColumns={ 
      @JoinColumn(name="BBIDBB") 
      } 
     ) 
    private Set<Bb> bbs; 

我的测试，第一次工作，第二次没有。

第一：

Session session; 
     SessionFactory sf_ORA = new Configuration().configure(
       "hibernate.cfg.ora.xml").buildSessionFactory(); 
     session = sf_ORA.openSession(); 

//A 
     Aa a = new Aa(); 
     a.setDescr("A1"); 
     a.setBbs(new HashSet<Bb>()); 
     //B 
     Bb b1 = new Bb(); 
     b1.setCcs(new HashSet<Cc>()); 
     Bb b2 =new Bb(); 
     b2.setCcs(new HashSet<Cc>()); 
     b1.setDescr("B1"); 
     b2.setDescr("B2"); 
     //C 
     Cc c1 = new Cc(); 
     Cc c2 = new Cc(); 
     Cc c3 = new Cc(); 
     c1.setDescr("C1"); 
     c2.setDescr("C2"); 
     c3.setDescr("C3"); 
     //FILL B 
     b1.getCcs().add(c1); 
     b1.getCcs().add(c2); 
     b2.getCcs().add(c2); 
     b2.getCcs().add(c3); 
     //FILL A 
     a.getBbs().add(b1); 
     a.getBbs().add(b2); 

session.beginTransaction(); 
     try 
     { 
      session.save(a); 
      session.flush(); 
      session.getTransaction().commit(); 
     } 
     catch(HibernateException ex) 
     { 
      session.getTransaction().rollback(); 
      throw ex; 
     } 

这做正确的工作： 休眠创造了我所有需要的语句：

Hibernate: insert into Aa (descr, idaa) values (?, ?) 
Hibernate: insert into Bb (descr, idbb) values (?, ?) 
Hibernate: insert into Cc (descr, idcc) values (?, ?) 
Hibernate: insert into Cc (descr, idcc) values (?, ?) 
Hibernate: insert into Bb (descr, idbb) values (?, ?) 
Hibernate: insert into Cc (descr, idcc) values (?, ?) 
Hibernate: insert into AA_BB (AAIDAA, BBIDBB) values (?, ?) 
Hibernate: insert into AA_BB (AAIDAA, BBIDBB) values (?, ?) 
Hibernate: insert into BB_CC (BBIDBB, CCIDCC) values (?, ?) 
Hibernate: insert into BB_CC (BBIDBB, CCIDCC) values (?, ?) 
Hibernate: insert into BB_CC (BBIDBB, CCIDCC) values (?, ?) 
Hibernate: insert into BB_CC (BBIDBB, CCIDCC) values (?, ?) 

连接结果查询是正确的：

A1 | B1 | C1

A1 | B1 | C2

A1 | B2 | C2

A1 | B2 | C3

二（TA-丹这是问题）从DB 读B1添加新的AA（A2），以B1.Aas集合添加新的抄送（c4）到B1.Ccs收集，更新B1。

Bb b1=null; 
     session.beginTransaction(); 
     try 
     { 
      Query qGetB1=session.createQuery("Select id from Bb where DESCR ='B1'"); 
      long idB1=(Long) qGetB1.list().get(0); 
      b1=(Bb) session.load(Bb.class, idB1); 
      session.flush(); 
      session.getTransaction().commit(); 
     } 
     catch(HibernateException ex) 
     { 
      session.getTransaction().rollback(); 
      throw ex; 
     } 

     Aa a2 = new Aa(); 
     a2.setDescr("A2"); 
     Cc c4 = new Cc(); 
     c4.setDescr("C4"); 

     b1.getAas().add(a2); 
     b1.getCcs().add(c4); 


     session.beginTransaction(); 
     try 
     { 
      session.flush(); 
      session.saveOrUpdate(b1); 
      session.flush(); 
      session.getTransaction().commit(); 
     } 
     catch(HibernateException ex) 
     { 
      session.getTransaction().rollback(); 
      throw ex; 
     } 

生成Hibernate的：

Hibernate: select bb0_.idbb as col_0_0_ from Bb bb0_ where DESCR='B1' //SEARCH B1 ID 
Hibernate: select bb0_.idbb as idbb1_0_, bb0_.descr as descr1_0_ from Bb bb0_ where bb0_.idbb=? //GET B1 
Hibernate: select aas0_.BBIDBB as BBIDBB1_1_, aas0_.AAIDAA as AAIDAA1_, aa1_.idaa as idaa0_0_, aa1_.descr as descr0_0_ from AA_BB aas0_, Aa aa1_ where aas0_.AAIDAA=aa1_.idaa and aas0_.BBIDBB=? GET B1.Aas 
Hibernate: select ccs0_.BBIDBB as BBIDBB1_1_, ccs0_.CCIDCC as CCIDCC1_, cc1_.idcc as idcc2_0_, cc1_.descr as descr2_0_ from BB_CC ccs0_, Cc cc1_ where ccs0_.CCIDCC=cc1_.idcc and ccs0_.BBIDBB=? GET B1.Ccs 
Hibernate: insert into Aa (descr, idaa) values (?, ?) //OK 
Hibernate: insert into Cc (descr, idcc) values (?, ?) //OK 
Hibernate: insert into BB_CC (BBIDBB, CCIDCC) values (?, ?) //OK 


... What about AA_BB record???? //!!!!!!!! 

为什么joinTable AA_BB未填充？

谢谢大家的关注。 Regards， Francesco。

Answer 1

如果您有双向关联，则一侧是所有者一方（没有mappedBy属性的那一面），另一面是反面（具有mappedBy属性的那一面）。

Hibernate只考虑所有者方知道两个实体之间是否存在关联。因此，如果A是A和B之间关系的所有者方，则必须将B实例添加到A的集合中以使关联持久化。将实例添加到B的集合中不起作用。

一般来说，你负责维护的对象图的一致性，从而你应该确保业主方（至少）会更新。