12 Replies Latest reply on Aug 7, 2007 6:56 PM by Ignacio de Cordoba

    Entity relationship and remove operations

    Karstem Strunk Newbie

      Hello,

      I have a problem with entity relationships and foreign key constraints. I want to get all child entities deleted when the parent entity is deleted. Therefore I used the CasecadeType.REMOVE, but it doesn't work.

      Here is code fragment:

      @Entity
      @Table(name = "Users")
      public class User implements Serializable {
      
       private int id;
      
       private List<ChatMessage> sentChatMessages;
       private List<ChatMessage> receivedChatMessages;
      
       @Id
       @GeneratedValue(strategy = GenerationType.IDENTITY)
       @Column(name = "id", updatable = false, nullable = false)
       public int getId() {
       return id;
       }
      
       @OneToMany(mappedBy = "sender", cascade = {CascadeType.REMOVE}, fetch = FetchType.LAZY)
       public List<ChatMessage> getSentChatMessages() {
       return this.sentChatMessages;
       }
      
       public void setSentChatMessages(List<ChatMessage> sentChatMessages) {
       this.sentChatMessages = sentChatMessages;
       }
      
       @OneToMany(mappedBy = "receipient", cascade = {CascadeType.REMOVE}, fetch = FetchType.LAZY)
       public List<ChatMessage> getReceivedChatMessages() {
       return this.receivedChatMessages;
       }
      
       public void setReceivedChatMessages(List<ChatMessage> receivedChatMessages) {
       this.receivedChatMessages = receivedChatMessages;
       }
      }
      


      @Entity
      @Table(name = "ChatMessages")
      public class ChatMessage implements Serializable {
      
       private User sender;
      
       private User receipient;
      
       private String message;
      
       @ManyToOne()
       @JoinColumn(name = "sender", referencedColumnName = "id", nullable = false)
       public User getSender() {
       return this.sender;
       }
      
       public void setSender(User sender) {
       this.sender = sender;
       }
      
       @ManyToOne()
       @JoinColumn(name = "receipient", referencedColumnName = "id", nullable = false)
       public User getReceipient() {
       return this.receipient;
       }
      
       public void setReceipient(User receipient) {
       this.receipient = receipient;
       }
      }
      


      When I try to delete a user, I exspect that all his messages are also deleted, but this does not happen. Instead I get the following exception:

      12:12:43,703 ERROR [JDBCExceptionReporter] ERROR: update or delete on "users" violates foreign key constraint "fk278c74e4eedef195" on "chatmessages"
      Detail: Key (id)=(12) is still referenced from table "chatmessages".
      12:12:43,703 ERROR [AbstractFlushingEventListener] Could not synchronize database state with session
      org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
      at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
      at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
      at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:249)
      at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:92)
      at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:87)
      at org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:218)
      at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2414)
      at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:2632)
      at org.hibernate.action.EntityDeleteAction.execute(EntityDeleteAction.java:73)
      at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:248)
      at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:232)
      at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:144)
      at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
      at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
      at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
      at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
      at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:515)
      at org.jboss.tm.TransactionImpl.doBeforeCompletion(TransactionImpl.java:1491)
      at org.jboss.tm.TransactionImpl.beforePrepare(TransactionImpl.java:1110)
      at org.jboss.tm.TransactionImpl.commit(TransactionImpl.java:324)
      at org.jboss.tm.TxManager.commit(TxManager.java:240)
      at org.jboss.aspects.tx.TxPolicy.endTransaction(TxPolicy.java:175)
      at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:87)
      at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
      at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:102)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:47)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
      at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
      at org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:263)
      at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106)
      at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82)
      at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:828)
      at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:681)
      at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:358)
      at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:412)
      at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:239)
      Caused by: java.sql.BatchUpdateException: Batch-Eintrag 0 delete from Users where id=12 wurde abgebrochen. Rufen Sie getNextException auf, um die Ursache zu erfahren.
      at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2478)
      at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1298)
      at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:347)
      at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2540)
      at org.jboss.resource.adapter.jdbc.WrappedStatement.executeBatch(WrappedStatement.java:519)
      at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
      at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:242)
      ... 41 more

      What can I do? I tried to remove all user's messages with the entityManager before removing the user, but I had no luck.

      I use JBoss 4.0.5 and a Postgres 8.1 database.