Hibernate @ManyToMany, ошибка: связь не существует

Question

Я пытаюсь реализовать отношение «многие ко многим» с двумя сущностями: Книгой и Авторами.

Книга может быть написана несколькими авторами, и авторы могут написать несколько книг.

Но когда я пытаюсь сохранить книгу вместе с его авторами, я получаю ошибку: отношения "книга" не существует.

Подайте еще немного информации:

---

Сущность

BookEntity

package orm.model;

import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;

@Entity
public class Livre {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="livre_id")
    Long livre_id;


    @ManyToMany
    @JoinTable(
            name="livre_auteur",
            joinColumns = {@JoinColumn(referencedColumnName = "livre_id")},
            inverseJoinColumns = {@JoinColumn(referencedColumnName = "auteur_id")}
    )
    private List<Auteur> auteurs;

    private String title;


    public Livre() {

    }   


    public Long getLivre_id() {
        return livre_id;
    }

    public void setLivre_id(Long livre_id) {
        this.livre_id = livre_id;
    }

    public List<Auteur> getAuteurs() {
        return auteurs;
    }

    public void setAuteurs(List<Auteur> auteurs) {
        this.auteurs = auteurs;
    }

    public String getTitle() {
        return title;
    }


    public void setTitle(String title) {
        this.title = title;
    }

}

AuthorEntity

package orm.model;

import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Entity(name="Auteur")
@Table(name="auteur")
public class Auteur {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="auteur_id")
    private Long auteur_id;
    private String name;
    private String surName;

    @ManyToMany(mappedBy="auteurs")
    private List<Livre> livres;


    public Auteur() {

    }


    public List<Livre> getLivres() {
        return livres;
    }

    public void setLivres(List<Livre> livres) {
        this.livres = livres;
    }

    public Long getAuteur_id() {
        return auteur_id;
    }


    public void setAuteur_id(Long auteur_id) {
        this.auteur_id = auteur_id;
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSurName() {
        return surName;
    }
    public void setSurName(String surName) {
        this.surName = surName;
    }


}

---

DAO

Общий Дао:

package orm.dao;

import javax.persistence.EntityManager;

import orm.helper.Helper;

public class GenericDao {

    private EntityManager entityManager;

    public GenericDao() {
        this.entityManager = Helper.createEntityManager();
    }


    protected EntityManager getEntityManager() {

        if(entityManager!=null || !entityManager.isOpen()) {
            entityManager = Helper.createEntityManager();
        }

        return entityManager;
    }

}

Автор Dao:

package orm.dao;

import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.TypedQuery;

import orm.exception.AlreadyExistsException;
import orm.helper.Helper;
import orm.model.Auteur;

public class AuteurDao extends GenericDao {

    public Auteur insert(Auteur auteur) throws AlreadyExistsException {
        EntityManager entityManager = getEntityManager();

        //check if Auteur exists
        Auteur existingAuteur = findById(auteur.getAuteur_id());

        if(existingAuteur!=null) {
            throw new AlreadyExistsException("l'auteur existe déjà dans la base de donnée, id : " + auteur.getAuteur_id());
        }

        Helper.beginTransaction(entityManager);
        entityManager.persist(auteur);
        Helper.commitTransactionAndClose(entityManager);
        return auteur;  
    }

    private Auteur findById(Long id) {
        TypedQuery<Auteur> query = getEntityManager().createQuery("from Auteur a where a.auteur_id = :id", Auteur.class);
        query.setParameter("id", id);

        try {
            return query.getSingleResult();
        } catch (NoResultException e) {
            return null;
        }

    }
}

Книга Дао:

package orm.dao;

import javax.persistence.EntityManager;
import javax.persistence.TypedQuery;

import orm.exception.AlreadyExistsException;
import orm.helper.Helper;
import orm.model.Livre;

public class LivreDao extends GenericDao{

    public Livre insert(Livre livre) throws AlreadyExistsException{

        EntityManager entityManager = getEntityManager();

        //test if livre already exist
        Livre existingLivre = findByNumber(livre.getLivre_id());

        if(existingLivre!=null) {
            throw new AlreadyExistsException("livre already in database with id : " + livre.getLivre_id());
        }

        Helper.beginTransaction(entityManager);
        entityManager.persist(livre);
        Helper.commitTransactionAndClose(entityManager);
        return livre;

    }


    private Livre findByNumber(Long id) {

        TypedQuery<Livre> query = getEntityManager().createQuery("from Livre l where l.livre_id = :id", Livre.class);
        query.setParameter("id", id);

        try {
            return query.getSingleResult();
        } catch (Exception e) {
            return null;
        }


    }
}

---

Main

package orm;

import java.util.ArrayList;
import java.util.List;

import orm.dao.LivreDao;
import orm.exception.AlreadyExistsException;
import orm.model.Auteur;
import orm.model.Livre;

public class Main {

    public static void main(String[] args) throws AlreadyExistsException {

        //1st author
        Auteur jSlater = new Auteur();
        jSlater.setName("Jack");
        jSlater.setSurName("Slater");

        //2nd author
        Auteur jBegood = new Auteur();
        jBegood.setName("Begood");
        jBegood.setSurName("Johnny");

        //author list
        List<Auteur> auteurs = new ArrayList<Auteur>();
        auteurs.add(jSlater);
        auteurs.add(jBegood);

        //book
        Livre livre = new Livre();
        //set multiple authors to book
        livre.setTitle("la chèvre enchantée");
        livre.setAuteurs(auteurs);

        // create Livre lists
        List<Livre> livreList1 = new ArrayList<>();
        livreList1.add(livre);

        List<Livre> livreList2 = new ArrayList<>();
        livreList2.add(livre);

        // populate to previously created Acteurs 
        jSlater.setLivres(livreList1);
        jBegood.setLivres(livreList2); 

        // then save
        LivreDao livreDao = new LivreDao();
        livreDao.insert(livre);

    }

}

---

трассировка стека ошибок:

avr. 18, 2019 7:59:30 PM org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformation
INFO: HHH000204: Processing PersistenceUnitInfo [
    name: entrainement
    ...]
avr. 18, 2019 7:59:30 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.12.Final}
avr. 18, 2019 7:59:30 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
avr. 18, 2019 7:59:30 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
avr. 18, 2019 7:59:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
avr. 18, 2019 7:59:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [org.postgresql.Driver] at URL [jdbc:postgresql://localhost:5432/entrainement-orm]
avr. 18, 2019 7:59:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=postgres, password=****}
avr. 18, 2019 7:59:30 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
avr. 18, 2019 7:59:30 PM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
avr. 18, 2019 7:59:30 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.PostgreSQL81Dialect
avr. 18, 2019 7:59:31 PM org.hibernate.engine.jdbc.env.internal.LobCreatorBuilderImpl useContextualLobCreation
INFO: HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
avr. 18, 2019 7:59:32 PM org.hibernate.hql.internal.QueryTranslatorFactoryInitiator initiateService
INFO: HHH000397: Using ASTQueryTranslatorFactory
avr. 18, 2019 7:59:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 0, SQLState: 42P01
avr. 18, 2019 7:59:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: ERREUR: la relation « livre » n'existe pas
  Position : 74
avr. 18, 2019 7:59:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 0, SQLState: 42P01
avr. 18, 2019 7:59:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: ERREUR: la relation « livre » n'existe pas
  Position : 13
Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:149)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:164)
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:789)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:767)
    at orm.dao.LivreDao.insert(LivreDao.java:24)
    at orm.Main.main(Main.java:32)
Caused by: org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:178)
    at org.hibernate.id.insert.AbstractSelectingDelegate.performInsert(AbstractSelectingDelegate.java:45)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2919)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3490)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:626)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:280)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:261)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:306)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:318)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:275)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:182)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:113)
    at org.hibernate.jpa.event.internal.core.JpaPersistEventListener.saveWithGeneratedId(JpaPersistEventListener.java:67)
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:189)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:132)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:58)
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:782)
    ... 3 more
Caused by: org.postgresql.util.PSQLException: ERREUR: la relation « livre » n'existe pas
  Position : 13
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:562)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:420)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:366)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:175)
    ... 20 more

Некоторая помощь будет высоко оценена, С уважением, Алексис

Answer 1

Поскольку ваш @ManyToMany является двунаправленным, для каждого из Autors вам необходимо заполнить список Livre, который будет содержать одну запись в приведенном выше примере:

    //book
    Livre livre = new Livre();
    //set multiple authors to book
    livre.setAuteurs(auteurs);
    livre.setTitle("la chèvre enchantée");

    // create Livre lists
    List<Livre> livreList1 = new ArrayList<>();
    livreList1.add(livre);

    List<Livre> livreList2 = new ArrayList<>();
    livreList2.add(livre);

    // populate to previously created Acteurs 
    jSlater.setLivres(livreList1);
    jBegood.setLivres(livreList2); 

    // then save
    LivreDao livreDao = new LivreDao();
    livreDao.insert(livre);