java - ManyToMany HQL Join - 连接的预期路径

Question

我有以下实体:

1.用户实体。

 @Entity
    @Table(name = "USER")
    public class User {

        @Id
        @GeneratedValue
        private int userId;

        @Column
        private String username;

        @Column
        private String password;

        @ManyToMany(fetch=FetchType.EAGER)
        @JoinTable(name = "USER_ROLE", joinColumns={@JoinColumn(name="userId")}, inverseJoinColumns={@JoinColumn(name="roleId")})
        private List<Role> roles;

//+setters and getters}

角色实体。

@Entity
@Table(name="ROLE")
public class Role {

    @Id
    @GeneratedValue
    private long roleId;

    @Column
    private String name;

    @ManyToMany(mappedBy="roles", fetch=FetchType.EAGER)
    private List<User> users;
//+setters and getters
}

现在，我尝试在存储库中提取用户(用户名)及其角色(角色名称)。我希望为 Spring Security Auth 执行此操作。 这是我的 HQL 代码:

@Query("select u.username, r.name from User u"+
            " join User_Role ur on u.userId = ur.userId"+
            " join Role r on ur.roleId = r.roleId"+
            " where u.username =:username")

...我收到此错误:

Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: Path expected for join! [select u.username, r.name from ro.app.mmapp.persistence.entity.User u join User_Role ur on u.userId = ur.userId join Role r on ur.roleId = r.roleId where u.username =:username]

我尝试了多种类型的连接，但得到了相同的结果。 谁能帮我一些建议？

谢谢!

Answer 1

任何基本的 JPQL 教程都会告诉您加入 ON A RELATION。

select u.username, r.name from User u JOIN u.roles r WHERE u.username =:username