hibernate @onetomany relationship updates instead of insert during save

问题

Please help me figure this out. I've tried so many combinations but nothing seems to work. I'm trying to implement hibernate mapping using annotations but during the saving of my parent object and its children i noticed that an update statement is being called instead of an insert statement.

I have two classes which have a one-to-many relationship with each other.

These are the class' mappings: Receipt has one-to-many Collections

@Entity
public class Receipt implements Serializable {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    @OneToMany
    @JoinColumn(name="ReceiptId")
    private List<Collection> collections;

    //setters, getters
}


@Entity
public class Collection implements Serializable{

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    @ManyToOne
    @JoinColumn(name="ReceiptId", insertable=false, updatable=false)
    private Receipt receipt;

    //setters getters
}

The problem is during saving a receipt like:

Receipt r = new Receipt();
List<Collection> cols = new ArrayList<Collection>();
cols.add(new Collection());
r.setCollections(cols);
getHibernateTemplate().save(r);

It generates this error:

Hibernate: insert into Receipt (userId, dateCreated, payor, receiptDate, receiptNumber, total) values (?, ?, ?, ?, ?, ?)
Hibernate: update Collection set ReceiptId=? where id=?
Nov 15, 2010 8:46:00 PM org.hibernate.jdbc.BatchingBatcher doExecuteBatch
SEVERE: Exception executing batch: 
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:171)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
    at org.springframework.orm.hibernate3.HibernateTemplate$28.doInHibernate(HibernateTemplate.java:883)
    at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
    at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374)
    at org.springframework.orm.hibernate3.HibernateTemplate.flush(HibernateTemplate.java:881)
    at com.coa.acctreports.daoImp.AccountingReportsImpl.update(AccountingReportsImpl.java:52)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)

回答1:

In the case of bidirectional many-to-one/one-to-many relationship, "many" side should be the owning side (and @JoinColumn is specified at the owning side), whereas "one" side should have mappedBy poiniting to the owning side. In your case you also need to enable cascading of the save operation:

@Entity 
public class Receipt implements Serializable { 
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "receipt")
    private List<Collection> collections; 
    ...
}      

@Entity 
public class Collection implements Serializable { 
    @ManyToOne 
    @JoinColumn(name="ReceiptId") 
    private Receipt receipt; 
    ...
} 

See also:

• Hibernate Annotations reference, section 2.2.5.3.1.1

来源：https://stackoverflow.com/questions/4184980/hibernate-onetomany-relationship-updates-instead-of-insert-during-save