Hibernate EntityManager ManyToMany

一対多サンプル（Hibernate）

ポイント：
１、Joinテーブル：JOIN_DELEGATE_EVENT
２、EventとDelegateテーブル

Event.java

package com.test;

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

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

@Entity
public class Event {
    private int eventId;
    private String eventName;
    private List<Delegate> delegates = new ArrayList<Delegate>();

    @Id
    @GeneratedValue
    public int getEventId() {
        return eventId;
    }

    public void setEventId(int eventId) {
        this.eventId = eventId;
    }

    public String getEventName() {
        return eventName;
    }

    public void setEventName(String eventName) {
        this.eventName = eventName;
    }

    @ManyToMany
    @JoinTable(name = "JOIN_DELEGATE_EVENT", joinColumns = {
        @JoinColumn(name = "eventId")
    }, inverseJoinColumns = {
        @JoinColumn(name = "delegateId")
    })
    public List<Delegate> getDelegates() {
        return delegates;
    }

    public void setDelegates(List<Delegate> delegates) {
        this.delegates = delegates;
    }
}

Delegate.java

package com.test;

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

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

@Entity
public class Delegate {
    private int delegateId;
    private String delegateName;
    private List<Event> events = new ArrayList<Event>();

    @Id
    @GeneratedValue
    public int getDelegateId() {
        return delegateId;
    }

    public void setDelegateId(int delegateId) {
        this.delegateId = delegateId;
    }

    public String getDelegateName() {
        return delegateName;
    }

    public void setDelegateName(String delegateName) {
        this.delegateName = delegateName;
    }

    @ManyToMany
    @JoinTable(name = "JOIN_DELEGATE_EVENT", joinColumns = {
        @JoinColumn(name = "delegateId")
    }, inverseJoinColumns = {
        @JoinColumn(name = "eventId")
    })
    public List<Event> getEvents() {
        return events;
    }

    public void setEvents(List<Event> events) {
        this.events = events;
    }
}

EventTest.java

package com.test;

import static org.junit.Assert.*;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class EventTest {

    static EntityManagerFactory entityManagerFactory;

    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        entityManagerFactory = Persistence
                .createEntityManagerFactory("org.hibernate.tutorial.jpa");
    }

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
        entityManagerFactory.close();
    }

    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void test() {
        EntityManager entityManager = entityManagerFactory
                .createEntityManager();
        entityManager.getTransaction().begin();

        try {
            Delegate d1 = new Delegate();
            d1.setDelegateName("d1");
            Delegate d2 = new Delegate();
            d2.setDelegateName("d2");
            Delegate d3 = new Delegate();
            d3.setDelegateName("d3");
            Delegate d4 = new Delegate();
            d4.setDelegateName("d4");

            Event e1 = new Event();
            e1.setEventName("java");
            Event e2 = new Event();
            e2.setEventName("c#");
            Event e3 = new Event();
            e3.setEventName("vb");

            e1.getDelegates().add(d1);
            e1.getDelegates().add(d2);
            e2.getDelegates().add(d2);
            e2.getDelegates().add(d3);
            e3.getDelegates().add(d3);
            e3.getDelegates().add(d4);

            entityManager.persist(e1);
            entityManager.persist(e2);
            entityManager.persist(e3);
            entityManager.persist(d1);
            entityManager.persist(d2);
            entityManager.persist(d3);
            entityManager.persist(d4);

            entityManager.getTransaction().commit();
        }
        catch (Exception e) {
            entityManager.getTransaction().rollback();
        }
    }
}

Delegate.sql

create table Delegate 
(
    delegateId int4 not null, 
    delegateName varchar(255), 
    primary key (delegateId)
)

delegateid	delegatename
4	d1
5	d2
6	d3
7	d4

Event.java

create table Event 
(
    eventId int4 not null, 
    eventName varchar(255), 
    primary key (eventId)
)

eventid	eventname
1	java
2	c#
3	vb

JOIN_DELEGATE_EVENT.java

create table JOIN_DELEGATE_EVENT 
(
    delegateId int4 not null, 
    eventId int4 not null
)

delegateid	eventid
4	1
5	1
5	2
6	2
6	3
7	3