ManyToMany
People 과 club 의 관계이다.
한 people은 여러 club 에 가입가능하고 한 club도 여러 people을 가입 받을 수 있다.
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CREATE TABLE `people` ( `PEOPLE_ID` int(11) NOT NULL AUTO_INCREMENT, `PEOPLE_NAME` varchar(45) NOT NULL, PRIMARY KEY (`PEOPLE_ID`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `club` ( `CLUB_ID` int(11) NOT NULL AUTO_INCREMENT, `CLUB_NAME` varchar(45) NOT NULL, PRIMARY KEY (`CLUB_ID`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `people_club` ( `PC_PEOPLE_ID` int(11) NOT NULL, `PC_CLUB_ID` int(11) NOT NULL, PRIMARY KEY (`PC_PEOPLE_ID`,`PC_CLUB_ID`), KEY `fk_people_club_club_idx` (`PC_CLUB_ID`), CONSTRAINT `fk_people_club_club` FOREIGN KEY (`PC_CLUB_ID`) REFERENCES `club` (`CLUB_ID`) ON DELETE CASCADE ON UPDATE CASCADE, CONSTRAINT `fk_people_club_people` FOREIGN KEY (`PC_PEOPLE_ID`) REFERENCES `people` (`PEOPLE_ID`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=utf8; |
ManyToMany(Bidirectional(양방향))
맵핑
관계 테이블(people_club)의 경우는 따로 접근하지 않을 경우는 맵핑하지 않아도 된다.
People
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package org.onecellboy.db.hibernate.table;
import java.util.LinkedList; import java.util.List;
import javax.persistence.Basic; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToMany; import javax.persistence.OneToMany; import javax.persistence.OneToOne; import javax.persistence.PrimaryKeyJoinColumn; import javax.persistence.Table;
@Entity @Table(name="people") public class People_Bi {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="PEOPLE_ID",columnDefinition="INT") private int id;
@Column(name="PEOPLE_NAME",columnDefinition="VARCHAR(45)") private String name;
@OneToMany(fetch=FetchType.LAZY,mappedBy="people", cascade = CascadeType.ALL,orphanRemoval=true) private List<Car_Bi> cars = new LinkedList<Car_Bi>();
@ManyToMany(fetch=FetchType.LAZY,mappedBy="peoples", cascade = CascadeType.ALL) private List<Club_Bi> clubs = new LinkedList<Club_Bi>();
public List<Club_Bi> getClubs() { return clubs; }
public void setClubs(List<Club_Bi> clubs) { this.clubs = clubs; }
public int getId() { return id; }
public void setId(int id) { this.id = id; }
public String getName() { return name; }
public void setName(String name) { this.name = name; }
} |
설명
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@ManyToMany(fetch=FetchType.LAZY,mappedBy="peoples", cascade = CascadeType.ALL) private List<Club_Bi> clubs = new LinkedList<Club_Bi>(); |
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fetch=FetchType.LAZY : Lazy Loading 하겠다는 것이다.
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club
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package org.onecellboy.db.hibernate.table;
import java.util.LinkedList; import java.util.List;
import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.ManyToOne; import javax.persistence.Table;
@Entity @Table(name="club") public class Club_Bi {
@Id @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="CLUB_ID",columnDefinition="INT") private int id;
@Column(name="CLUB_NAME",columnDefinition="VARCHAR(45)") private String name;
@ManyToMany(fetch=FetchType.LAZY /*, cascade = CascadeType.ALL*/) @JoinTable( name="people_club", joinColumns= {@JoinColumn(name="PC_CLUB_ID",referencedColumnName="CLUB_ID")}, inverseJoinColumns= { @JoinColumn(name="PC_PEOPLE_ID",referencedColumnName="PEOPLE_ID")} ) private List<People_Bi> peoples = new LinkedList<People_Bi>() ;
public int getId() { return id; }
public void setId(int id) { this.id = id; }
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public List<People_Bi> getPeoples() { return peoples; }
public void setPeoples(List<People_Bi> peoples) { this.peoples = peoples; }
} |
설명
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@ManyToMany(fetch=FetchType.LAZY /*, cascade = CascadeType.ALL*/) @JoinTable( name="people_club", joinColumns= {@JoinColumn(name="PC_CLUB_ID",referencedColumnName="CLUB_ID")}, inverseJoinColumns= { @JoinColumn(name="PC_PEOPLE_ID",referencedColumnName="PEOPLE_ID")} ) |
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@ManyToOne : 다대일 관계라는 것이다.
inverseJoinColumns= { @JoinColumn(name="PC_PEOPLE_ID",referencedColumnName="PEOPLE_ID") : 관계(join) 테이블에서 그 반대 관계를 뜻한다. people 테이블과 people_club 테이블과의 관계이다. 여기도 마찬가지로 people_club 테이블이 people 테이블을 참조한다. name은 people_club의 컬럼명, referencedColumnName 은 people 테이블의 컬럼명이다. |
테스트
테스트 코드
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package org.onecellboy.db.hibernate;
import static org.junit.Assert.*;
import java.io.File;
import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.boot.MetadataSources; import org.hibernate.boot.registry.StandardServiceRegistry; import org.hibernate.boot.registry.StandardServiceRegistryBuilder; import org.junit.After; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; import org.onecellboy.db.hibernate.table.Club_Bi; import org.onecellboy.db.hibernate.table.People_Bi;
public class ManyToManyBi {
static SessionFactory sessionFactory = null; static StandardServiceRegistry registry = null;
static int select_id = 0;
@BeforeClass public static void setUp() { registry = new StandardServiceRegistryBuilder().configure(new File("./conf/hibernate/hibernate.cfg.xml")) .build(); sessionFactory = new MetadataSources(registry).buildMetadata().buildSessionFactory();
}
@AfterClass public static void setDown() { sessionFactory.close(); }
@After public void testAfter() { System.out.println(); System.out.println(); }
@Test public void test() {
int temp_id1= -1; int temp_id2= -1; int temp_id3= -1;
Session session =null; Transaction tx = null;
System.out.println("======Insert TEST======"); System.out.println("======1. People1 은 club들 추가, club들은 people1을 추가하지 않음 ( 한방향에서만 관계생성 ) ======"); System.out.println("======2. People2, people3 은 club들 추가, club들은 people2을 추가 ( 양방향에서 관계생성 ) ======");
session = sessionFactory.openSession(); tx = session.beginTransaction();
People_Bi people1 = new People_Bi(); people1.setName("sun 1");
People_Bi people2 = new People_Bi(); people2.setName("sun 2");
People_Bi people3 = new People_Bi(); people3.setName("sun 3");
Club_Bi club1 = new Club_Bi(); club1.setName("soccer");
Club_Bi club2 = new Club_Bi(); club2.setName("soccer");
people1.getClubs().add(club1); people1.getClubs().add(club2);
people2.getClubs().add(club1); people2.getClubs().add(club2); club1.getPeoples().add(people2); club2.getPeoples().add(people2);
people3.getClubs().add(club1); people3.getClubs().add(club2); club1.getPeoples().add(people3); club2.getPeoples().add(people3);
session.save(people1); session.save(people2); session.save(people3);
temp_id1 = people1.getId(); temp_id2 = people2.getId(); temp_id3 = people3.getId();
tx.commit(); session.close();
System.out.println(); System.out.println("====== people1 과 people2 의 club 과의 관계 확인 ======"); session = sessionFactory.openSession(); tx = session.beginTransaction();
people1 = session.get(People_Bi.class, temp_id1); people2 = session.get(People_Bi.class, temp_id2);
// people1 은 club 과의 관계가 없다. 양방향 관계인데 양방향에서 관계를 설정하지 않았지 때문.. System.out.println("people1 club size = "+ people1.getClubs().size());
// people2 은 club 과의 관계가 존재한다. 양방향에서 관계를 설정하였기 때문이다. System.out.println("people2 club size = "+ people2.getClubs().size());
tx.commit(); session.close();
System.out.println(); System.out.println(); System.out.println("====== people과 club 의 관계 제거 ======"); System.out.println("people2에서 club1의 관계를 제거할 경우");
session = sessionFactory.openSession(); tx = session.beginTransaction();
people2 = session.get(People_Bi.class, temp_id2); Club_Bi remove = people2.getClubs().remove(0); remove.getPeoples().remove(people2);
// 양방향이므로 서로가 서로를 양방향에서 관계를 제거해야한다. session.saveOrUpdate(people2);
tx.commit(); session.close();
System.out.println(); System.out.println(); System.out.println("====== people 제거 ======"); System.out.println("people2삭제시 people3는 어찌되는가?");
session = sessionFactory.openSession(); tx = session.beginTransaction();
people3 = session.get(People_Bi.class, temp_id3); System.out.println("people2삭제전 people3의 club 갯수 = "+people3.getClubs().size());
tx.commit(); session.close();
session = sessionFactory.openSession(); tx = session.beginTransaction();
people2 = session.get(People_Bi.class, temp_id2); session.delete(people2);
tx.commit(); session.close();
session = sessionFactory.openSession(); tx = session.beginTransaction();
people3 = session.get(People_Bi.class, temp_id3); System.out.println("people2삭제후 people3의 club 갯수 = "+people3.getClubs().size());
tx.commit(); session.close();
}
} |
결과
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======Insert TEST====== ======1. People1 은 club들 추가, club들은 people1을 추가하지 않음 ( 한방향에서만 관계생성 ) ====== ======2. People2, people3 은 club들 추가, club들은 people2을 추가 ( 양방향에서 관계생성 ) ====== Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into club (CLUB_NAME) values (?) Hibernate: insert into club (CLUB_NAME) values (?) Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?)
====== people1 과 people2 의 club 과의 관계 확인 ====== Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people1 club size = 0 Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people2 club size = 2
====== people과 club 의 관계 제거 ====== people2에서 club1의 관계를 제거할 경우 Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? Hibernate: select peoples0_.PC_CLUB_ID as PC_CLUB_1_4_0_, peoples0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, people_bi1_.PEOPLE_ID as PEOPLE_I1_2_1_, people_bi1_.PEOPLE_NAME as PEOPLE_N2_2_1_ from people_club peoples0_ inner join people people_bi1_ on peoples0_.PC_PEOPLE_ID=people_bi1_.PEOPLE_ID where peoples0_.PC_CLUB_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: delete from people_club where PC_CLUB_ID=? Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?)
====== people 제거 ====== people2삭제시 people3는 어찌되는가? Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people2삭제전 people3의 club 갯수 = 2 Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select cars0_.PC_PEOPLE_ID as PC_PEOPL2_3_0_, cars0_.PC_CAR_ID as PC_CAR_I1_3_0_, car_bi1_.CAR_ID as CAR_ID1_0_1_, car_bi1_.CAR_NAME as CAR_NAME2_0_1_, car_bi1_1_.PC_PEOPLE_ID as PC_PEOPL2_3_1_ from people_car cars0_ inner join car car_bi1_ on cars0_.PC_CAR_ID=car_bi1_.CAR_ID left outer join DB_TEST.people_car car_bi1_1_ on car_bi1_.CAR_ID=car_bi1_1_.PC_CAR_ID where cars0_.PC_PEOPLE_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? Hibernate: select phones0_.PHONE_OWNER_ID as PHONE_OW3_6_0_, phones0_.PHONE_ID as PHONE_ID1_6_0_, phones0_.PHONE_ID as PHONE_ID1_6_1_, phones0_.PHONE_NUMBER as PHONE_NU2_6_1_, phones0_.PHONE_OWNER_ID as PHONE_OW3_6_1_ from phone phones0_ where phones0_.PHONE_OWNER_ID=? Hibernate: delete from people_club where PC_CLUB_ID=? Hibernate: delete from club where CLUB_ID=? Hibernate: delete from people where PEOPLE_ID=? Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people2삭제후 people3의 club 갯수 = 1 |
설명
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테스트코드 |
people1.getClubs().add(club1); people1.getClubs().add(club2);
people2.getClubs().add(club1); people2.getClubs().add(club2); club1.getPeoples().add(people2); club2.getPeoples().add(people2);
people3.getClubs().add(club1); people3.getClubs().add(club2); club1.getPeoples().add(people3); club2.getPeoples().add(people3);
session.save(people1); session.save(people2); session.save(people3);
people1 = session.get(People_Bi.class, temp_id1); people2 = session.get(People_Bi.class, temp_id2);
// people1 은 club 과의 관계가 없다. 양방향 관계인데 양방향에서 관계를 설정하지 않았지 때문.. System.out.println("people1 club size = "+ people1.getClubs().size());
// people2 은 club 과의 관계가 존재한다. 양방향에서 관계를 설정하였기 때문이다. System.out.println("people2 club size = "+ people2.getClubs().size());
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결과 |
Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into club (CLUB_NAME) values (?) Hibernate: insert into club (CLUB_NAME) values (?) Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into people (PEOPLE_NAME) values (?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?) Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?)
Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people1 club size = 0 Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people2 club size = 2
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설명 |
people1 에서 club 과의 관계는 people1 한쪽만 설정했다. 그 결과 people1과 관계된 club 은 insert 되었으나 관계인 people_club 에는 관계가 insert 되지 않았다. 즉 people1은 관계된 club이 없었다. |
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테스트코드 |
people2 = session.get(People_Bi.class, temp_id2); Club_Bi remove = people2.getClubs().remove(0); remove.getPeoples().remove(people2);
// 양방향이므로 서로가 서로를 양방향에서 관계를 제거해야한다. session.saveOrUpdate(people2);
people3 = session.get(People_Bi.class, temp_id3); System.out.println("people2삭제전 people3의 club 갯수 = "+people3.getClubs().size());
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결과 |
Hibernate: delete from people_club where PC_CLUB_ID=? Hibernate: insert into people_club (PC_CLUB_ID, PC_PEOPLE_ID) values (?, ?)
====== people 제거 ====== people2삭제시 people3는 어찌되는가? Hibernate: select people_bi0_.PEOPLE_ID as PEOPLE_I1_2_0_, people_bi0_.PEOPLE_NAME as PEOPLE_N2_2_0_ from people people_bi0_ where people_bi0_.PEOPLE_ID=? Hibernate: select people_inf0_.PEOPLE_INFO_ID as PEOPLE_I1_5_0_, people_inf0_.PEOPLE_INFO_AGE as PEOPLE_I2_5_0_, people_inf0_.PEOPLE_INFO_BIRTHDAY as PEOPLE_I3_5_0_ from people_info people_inf0_ where people_inf0_.PEOPLE_INFO_ID=? Hibernate: select clubs0_.PC_PEOPLE_ID as PC_PEOPL2_4_0_, clubs0_.PC_CLUB_ID as PC_CLUB_1_4_0_, club_bi1_.CLUB_ID as CLUB_ID1_1_1_, club_bi1_.CLUB_NAME as CLUB_NAM2_1_1_ from people_club clubs0_ inner join club club_bi1_ on clubs0_.PC_CLUB_ID=club_bi1_.CLUB_ID where clubs0_.PC_PEOPLE_ID=? people2삭제전 people3의 club 갯수 = 2 |
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설명 |
people과 club의 관계가 양방향 관계이므로 관계를 없애는 것도 양방향으로 이루어져야 한다. |
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테스트코드 |
people3 = session.get(People_Bi.class, temp_id3); System.out.println("people2삭제전 people3의 club 갯수 = "+people3.getClubs().size());
tx.commit(); session.close();
session = sessionFactory.openSession(); tx = session.beginTransaction();
people2 = session.get(People_Bi.class, temp_id2); session.delete(people2);
tx.commit(); session.close();
session = sessionFactory.openSession(); tx = session.beginTransaction();
people3 = session.get(People_Bi.class, temp_id3); System.out.println("people2삭제후 people3의 club 갯수 = "+people3.getClubs().size());
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결과 |
people2삭제전 people3의 club 갯수 = 2
Hibernate: delete from people_club where PC_CLUB_ID=? Hibernate: delete from club where CLUB_ID=? Hibernate: delete from people where PEOPLE_ID=?
people2삭제후 people3의 club 갯수 = 1 |
|
설명 |
people2와 people3는 같은 하나의 club과 관계되어 있다. CascadeType.ALL 옵션 때문에 people2를 삭제시 연관된 club들도 삭제되어야 한다. 이때 people3에도 같은 club이 관계되어 있다면 해당 club을 삭제할까? 삭제하지 않을까? |
ManyToMany(Unidirectional(단방향))
위의 양방향 예제에서 people에서 club으로의 관계만 없이 club에서 people로의 관계만 있는 형태이다.
행동은 단방향 ManyToOne과 동일하다.
따라서 예제는 작성하지 않는다.( 귀찮다 ㅜㅜ)
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