Проблема Owning Entity
.
Предполагая, что Staff
является подклассом User
, ваша проблема заключается в том, что только одна сторона отношений является владельцем объекта. mappedBy = "groupMemberList"
делает объект Group
владельцем, поэтому сохраняются только изменения этого объекта. Это означает, что вы должны обновить groupMemberList
в Group
сущности в обоих случаях. Если у вас есть список групп для User
, то вам нужно перебрать список групп и добавить к нему User
. groupList
в User
только для поиска.
Дано User
и GroupMember
сущностей:
@Entity
public class User {
@Id @GeneratedValue
private Long id;
@ManyToMany(mappedBy = "groupMemberList")
private List<GroupMember> groupList;
@Entity
public class GroupMember {
@Id @GeneratedValue
private Long id;
@ManyToMany
private List<User> groupMemberList;
Тогда:
// create starting user and membergroup
tx.begin();
User user = new User();
em.persist(user);
GroupMember group = new GroupMember();
em.persist(group);
tx.commit();
em.clear();
// update users for groupId 2
System.out.println("update users for groupId 2");
tx.begin();
List<User> users = new ArrayList<>();
users.add(user);
group.setGroupMemberList(users);
em.merge(group);
tx.commit();
em.clear();
// update groups for userId 1 -- doesn't work, not owner of relationship
System.out.println("update groups for userId 1 -- doesn't work, not owner of relationship");
tx.begin();
List<GroupMember> groups = new ArrayList<>();
groups.add(group);
user.setGroupList(groups);
em.merge(user);
tx.commit();
em.clear();
// update groups for userId 1 -- works
System.out.println("update groups for userId 1 -- works");
tx.begin();
for ( GroupMember groupMember: groups) {
groupMember.getGroupMemberList().add(user);
em.merge(groupMember);
}
tx.commit();
em.clear();
Дает следующий вывод SQL:
Hibernate: insert into User (id) values (?)
Hibernate: insert into GroupMember (id) values (?)
update users for groupId 2
Hibernate: select groupmembe0_.id as id1_0_0_ from GroupMember groupmembe0_ where groupmembe0_.id=?
Hibernate: select groupmembe0_.groupList_id as groupLis1_1_0_, groupmembe0_.groupMemberList_id as groupMem2_1_0_, user1_.id as id1_4_1_ from GroupMember_User groupmembe0_ inner join User user1_ on groupmembe0_.groupMemberList_id=user1_.id where groupmembe0_.groupList_id=?
Hibernate: select user0_.id as id1_4_0_ from User user0_ where user0_.id=?
Hibernate: insert into GroupMember_User (groupList_id, groupMemberList_id) values (?, ?)
update groups for userId 1 -- doesn't work, not owner of relationship
Hibernate: select user0_.id as id1_4_0_ from User user0_ where user0_.id=?
Hibernate: select groupmembe0_.id as id1_0_0_ from GroupMember groupmembe0_ where groupmembe0_.id=?
update groups for userId 1 -- works
Hibernate: select groupmembe0_.id as id1_0_0_ from GroupMember groupmembe0_ where groupmembe0_.id=?
Hibernate: select groupmembe0_.groupList_id as groupLis1_1_0_, groupmembe0_.groupMemberList_id as groupMem2_1_0_, user1_.id as id1_4_1_ from GroupMember_User groupmembe0_ inner join User user1_ on groupmembe0_.groupMemberList_id=user1_.id where groupmembe0_.groupList_id=?
Hibernate: delete from GroupMember_User where groupList_id=?
Hibernate: insert into GroupMember_User (groupList_id, groupMemberList_id) values (?, ?)
Hibernate: insert into GroupMember_User (groupList_id, groupMemberList_id) values (?, ?)
Ссылка: MappedBy в двунаправленном виде @ManyToMany: в чем причина
JPA - разница в использовании свойства mappedBy для определения объекта-владельца