Spring 更新多对多关系问题

Question

我正在尝试通过此 json 多对多更新我的实体： 正如你所看到的，我有这样的关系：Utente-Ruoli，Ruoli-Privileggi

• 我在 json DTO 中发送了 ruoli 的 id 列表和用户的 id

这是我的Utente JPA中的方法：

  @Modifying(flushAutomatically = true, clearAutomatically = true)
    @Transactional
    @Query("UPDATE Utente u SET u.roles = :roles WHERE u.id = :userId")
    int saveUserRoles(@Param("userId") Integer userId, @Param("roles") Set<Ruoli> roles);

这就是我提供服务的地方：

 public Utente addRolesToUser(RuoliDTO ruoliDTO) {
    log.info("{}.addRolesToUser adding user: {} to list roles: {}", this.getClass().getName(), ruoliDTO.getUser().getUsername(), ruoliDTO.getRoles().size());
    Utente utente = ruoliDTO.getUser();
    Set<Ruoli> rolesToAdd = ruoliDTO.getRoles();
    utente.setRoles(ruoliDTO.getRoles());
     userRepository.saveUserRoles(utente.getId(), rolesToAdd);
     return utente;
}

我总是遇到这个错误：

Parameter value [Ruoli{id=2, roleName='ADMIN', description='admin', privileggi=[Privileggi{id=1, privName='UNICACON_MDJS_USER', description='basic user', active=false}, Privileggi{id=3, privName='UNICACON_MDJS_ADMIN', description='admin role', active=true}, Privileggi{id=4, privName='ARCHICON_MDJS_USER', description='archicon role', active=true}]}] did not match expected type [java.util.Set (n/a)]; nested exception is java.lang.IllegalArgumentException: Parameter value [Ruoli{id=2, roleName='ADMIN', description='admin', privileggi=[Privileggi{id=1, privName='UNICACON_MDJS_USER', description='basic user', active=false}, Privileggi{id=3, privName='UNICACON_MDJS_ADMIN', description='admin role', active=true}, Privileggi{id=4, privName='ARCHICON_MDJS_USER', description='archicon role', active=true}]}] did not match expected type [java.util.Set (n/a)]

这些是我的实体：

     @Entity
    @Table(name = "utente")
@Data
    public class Utente implements Serializable {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
    
        @JsonIgnoreProperties("utenti")
        @ManyToMany(fetch = FetchType.EAGER, cascade = {CascadeType.MERGE, CascadeType.PERSIST})
        @JoinTable(
                name = "utente_ruolo",
                joinColumns = @JoinColumn(name = "utente_id", referencedColumnName = "id"),
                inverseJoinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id")
        )
        private List<Ruoli> roles;
    }



 @Data
    @Entity
    @Table(name = "ruoli")
    public class Ruoli implements Serializable {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
    
        @JsonIgnore
        @ManyToMany(cascade ={ CascadeType.MERGE, CascadeType.PERSIST})
        @JoinTable(
                name = "utente_ruolo",
                joinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id"),
                inverseJoinColumns = @JoinColumn(name = "utente_id", referencedColumnName = "id")
        )
        private List<Utente> utenti;
    }

    @Entity
    @Data
    @Table(name = "privileggi")
    public class Privileggi implements Serializable {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
    
        @Column(name = "priv_name")
        private String privName;
    
        @Column(name = "description")
        private String description;
    
        @Column(name = "active")
        private Boolean active;
    
        @JsonIgnore
        @ManyToMany( cascade ={ CascadeType.MERGE, CascadeType.PERSIST})
        @JoinTable(
                name = "ruolo_privileggi",
                joinColumns = @JoinColumn(name = "priv_id", referencedColumnName = "id"),
                inverseJoinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id")
        )
        private List<Ruoli> ruoli;
    }

我做错了什么？

Answer 1

以下是答案

• 首先，您需要从数据库中获取Utente实体。

• 然后，您可以使用 RuoliDTO 中的角色更新 Utente 实体的角色。

• 最后，您可以将更新后的Utente实体保存回数据库。

   public Utente addRolesToUser(RuoliDTO ruoliDTO) {
       log.info("{}.addRolesToUser adding user: {} to list roles: {}", this.getClass().getName(), ruoliDTO.getUser().getUsername(), ruoliDTO.getRoles().size());
  
       // 1. Fetch the Utente entity from the database.
       Utente utente = userRepository.findById(ruoliDTO.getUser().getId()).orElse(null);
  
       if (utente != null) {
           // 2. Update the Utente entity's roles with the roles from RuoliDTO.
           utente.setRoles(ruoliDTO.getRoles());
  
           // 3. Save the updated Utente entity back to the database.
           utente = userRepository.save(utente);
       }
  
       return utente;
   }
  

Answer 2

我不确定

UPDATE

是否是正确的操作，因为像这样更新多对多表并不常见。由于您要添加角色，因此应该是一个

INSERT

操作，如果您只想替换全部，请先执行

DELETE

。

如果您想进行批量

INSERT

来提高性能，请查看

saveAll

方法：https://stackoverflow.com/a/50882952/20991328