我有 3 个 bean:组织、角色、用户
角色 - 组织关系 - @ManyToOne
角色 - 用户关系 - @ManyToMany
组织:
@Entity
@Table(name = "entity_organization")
public class Organization implements Serializable {
private static final long serialVersionUID = -646783073824774092L;
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
Long id;
String name;
@OneToMany(targetEntity = Role.class, mappedBy = "organization")
List<Role> roleList;
...
作用:
@Entity
@Table(name = "entity_role")
public class Role implements Serializable {
private static final long serialVersionUID = -8468851370626652688L;
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
Long id;
String name;
String description;
@ManyToOne
Organization organization;
...
用户:
@Entity
@Table(name = "entity_user")
public class User implements Serializable {
private static final long serialVersionUID = -4353850485035153638L;
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
Long id;
@ManyToMany
@JoinTable(name = "entity_user_role",
joinColumns = @JoinColumn(name = "user_id", referencedColumnName = "id"),
inverseJoinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id"))
List<Role> roleList;
...
所以我需要获取指定用户的所有组织(首先我需要选择所有用户角色,然后选择所有具有该角色的组织)
我有一个实现此逻辑的 sql 语句(例如,我选择 id = 1 的用户):
SELECT * FROM entity_organization AS o
INNER JOIN entity_role r ON r.organization_id = o.id
INNER JOIN entity_user_role ur ON ur.role_id=r.id
WHERE ur.user_id = 1
我如何使用 hibernate 命名查询机制来实现它? 谢谢!
最佳答案
@NamedQuery
我在 Organization
实体类上创建了以下 @NamedQuery
。
@NamedQuery(name = "query", query = "SELECT DISTINCT o " +
"FROM Organization o, User u " +
"JOIN o.roles oRole " +
"JOIN u.roles uRole " +
"WHERE oRole.id = uRole.id AND u.id = :uId")
public class Organization { ...
(我使用标准的 JPA 注释,但我的提供程序是 Hibernate。)
测试
这是我运行的测试。
EntityManager em = ...
TypedQuery<Organization> q = em.createNamedQuery("query", Organization.class);
q.setParameter("uId", 1); // try it with 1L if Hibernate barks about it
for (Organization o : q.getResultList())
System.out.println(o.name);
使用下面的表格和示例数据,输出
A
B
请看看它是否适合你。
表格
CREATE TABLE `organization` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`)
);
CREATE TABLE `role` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`description` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`organization_id` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
);
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`)
);
CREATE TABLE `user_has_role` (
`user_id` int(11) NOT NULL DEFAULT '0',
`role_id` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`user_id`,`role_id`)
);
ALTER TABLE `role` ADD CONSTRAINT `cst_organization_id`
FOREIGN KEY `fk_organiztaion_id` (`organization_id`)
REFERENCES `organization` (`id`);
(我使用的与你的有点不同,但应该没有太大关系。)
示例数据
`organization`
+----+------+
| id | name |
+----+------+
| 1 | A |
| 2 | B |
+----+------+
`role`
+----+------+-------------+-----------------+
| id | name | description | organization_id |
+----+------+-------------+-----------------+
| 1 | A | a | 1 |
| 2 | B | b | 1 |
| 3 | C | c | 2 |
+----+------+-------------+-----------------+
`user`
+----+
| id |
+----+
| 1 |
| 2 |
| 3 |
+----+
`user_has_role`
+---------+---------+
| user_id | role_id |
+---------+---------+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 2 | 1 |
| 3 | 1 |
| 3 | 3 |
+---------+---------+
关于mysql - Hibernate 命名查询 - 连接 3 个表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8399379/