绑定两个实体,无需中间实体的 Spring Data JPA。

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英文:

Bind two Entity without intermediate Entity spring data jpa

问题

我有一个用户表(和实体)

create table users(
  id                              number(9)          not null,
  alias                           varchar2(200 char),
  name_en                         varchar2(200 char),
  state                           varchar2(1)        not null
);

以及用户组

create table user_groups(
  group_id                        number(9)          not null,
  alias                           varchar2(200)      not null,
  name_en                         varchar2(200 char),
  state                           varchar2(1)        not null,
  constraint user_groups1 primary key (group_id)
);

组用户存储在绑定表中

create table user_group_binds(
  group_id                        number(9)          not null,
  user_id                         number(9)          not null,
  constraint user_group_binds1 foreign key (group_id) references user_groups(group_id),
  constraint user_group_binds2 foreign key (user_id) references users(id)
);

我想要在我的组实体中拥有用户实体的列表(不包括绑定实体)。有任何想法吗?
当然,我可以使用@Query注释,但我有其他与组映射的实体,它们将自动获取组实体。
我可以覆盖自动生成的方法吗?

英文:

I have a user table(and entity)

create table users(
  id                              number(9)          not null,
  alias                           varchar2(200 char),
  name_en                         varchar2(200 char),
  state                           varchar2(1)        not null
);

and user groups

create table user_groups(
  group_id                        number(9)          not null,
  alias                           varchar2(200)      not null,
  name_en                         varchar2(200 char),
  state                           varchar2(1)        not null,
  constraint user_groups1 primary key (group_id)
);

group users are stored in bind table

create table user_group_binds(
  group_id                        number(9)          not null,
  user_id                         number(9)          not null,
  constraint user_group_binds1 foreign key (group_id) references user_groups(group_id),
  constraint user_group_binds2 foreign key (user_id) references users(id)
);

I want to have in my group entity list of userEntity(without bind entity). Any ideas?
Of course, I can use @Query annotation, but I have other entities who mapped with group and they will automatic get group entity.
Can I override automatical methods?

答案1

得分: 1

您可以使用 @JoinTable 并在 UserGroup 实体中定义与联接表的列映射。

@OneToMany(cascade = CascadeType.ALL)
@JoinTable(name = "user_group_binds",
    joinColumns = {@JoinColumn(name = "group_id", referencedColumnName = "group_id")},
    inverseJoinColumns = {@JoinColumn(name = "user_id", referencedColumnName = "id")})
List<UserEntity> users;
英文:

You can use @JoinTable and define column mapping with join table in UserGroup Enitity

  @OneToMany(cascade = CascadeType.ALL)
  @JoinTable(name = &quot;user_group_binds&quot;,
      joinColumns = {@JoinColumn(name = &quot;group_id&quot;, referencedColumnName = &quot;group_id&quot;)},
      inverseJoinColumns = {@JoinColumn(name = &quot;user_id&quot;, referencedColumnName = &quot;id&quot;)})
  List&lt;UserEntity&gt; users;

huangapple
  • 本文由 发表于 2020年7月30日 14:53:36
  • 转载请务必保留本文链接:https://go.coder-hub.com/63167718.html
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