JoinTable 双向关联后保存，关联表重复保存

来源：互联网发布：vivo深圳研发待遇知乎编辑：程序博客网时间：2024/06/06 11:04

双向table时：

如果双向关联后保存，会重复插入。

如果单向关联，就没问题。

或者，使用单向JoinTable，双向关联也不会重复插入。

@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY)@JoinTable(name="m_o_s",joinColumns = {@JoinColumn(name = "m")},inverseJoinColumns = {@JoinColumn(name="s")})

@ManyToOne( fetch = FetchType.LAZY)@JoinTable(name="m_o_s",joinColumns = {@JoinColumn(name = "s")},inverseJoinColumns = {@JoinColumn(name="m")})

单向保存，更新时：

OrgEntity orgEntity = new OrgEntity();orgEntity.setId(UUID.randomUUID().toString());Set<SpaceEntity> set = new HashSet<>();SpaceEntity spaceEntity = getSpaceEntity();spaceEntity.setOrg(orgEntity);set.add(spaceEntity);orgEntity.setSpaces(set);

Hibernate: insert into test.org (name, id) values (?, ?)

Hibernate: insert into test.space (name, id) values (?, ?)

Hibernate: insert into m_o_s (m, s) values (?, ?)

双向保存：

OrgEntity orgEntity = new OrgEntity();orgEntity.setId(UUID.randomUUID().toString());Set<SpaceEntity> set = new HashSet<>();SpaceEntity spaceEntity = getSpaceEntity();spaceEntity.setOrg(orgEntity);set.add(spaceEntity);orgEntity.setSpaces(set);

Hibernate: insert into test.org (name, id) values (?, ?)

Hibernate: insert into test.space (name, id) values (?, ?)

Hibernate: insert into m_o_s (m, s) values (?, ?)

0 0