Spring Boot JPA 一对多和多对一多表

Question

我有 5 个表，一个用户可以有许多模块/角色/工厂。 user_master 是包含用户详细信息的主表，user_roles 是包含模块/角色/工厂详细信息的子表。我的疑惑是如何在Model Class中写出关系。

user_master
------------
user_id int(10) unsigned
first_name  varchar(50)
last_name   varchar(50)
mail_id varchar(80)
user_status tinyint(4)
is_deleted  tinyint(4)
created_by  int(10)
created_date    date
modified_by int(10)
modified_date   date

user_roles
-----------
user_role_id    int(10) unsigned
user_id int(10) unsigned
module_master_id    int(10) unsigned
role_master_id  int(10) unsigned
plant_master_id int(10) unsigned

module_master:
module_master_id    int(10) unsigned
module_code int(10)
module_name varchar(50)
active_flag tinyint(4)

role_master:
role_master_id  int(10) unsigned
module_master_id    int(10) unsigned
role_code   int(10)
role_name   varchar(50)
active_flag tinyint(4)

plant_master:
plant_master_id int(10) unsigned
plant_code  int(10)
plant_name  varchar(50)
active_flag tinyint(4)

剩下的模块/角色/工厂都有自己的master，master_id是master表的主键。

我只想写user_master 和user_roles 模型类。需要一对多和多对一的映射。

Answer 1

对于一对多，您可以在您的实体类中拥有如下内容：

1. @OneToMany 在用户实体中

   @OneToMany(mappedBy = "user")
   private List<Role> roles;
   

2. @ManyToOne 在角色方面

   @ManyToOne
   @JoinColumn(name = "user")
   private User user;
   

   @ManyToMany

   @ManyToMany(cascade = { 
       CascadeType.PERSIST, 
       CascadeType.MERGE
   })
   @JoinTable(name = "user_role",
       joinColumns = @JoinColumn(name = "user_id"),
       inverseJoinColumns = @JoinColumn(name = "role_id")
   )
   private List<Role> roles= new ArrayList<>();
   

和角色方面：

    @ManyToMany(mappedBy = "role")
    private List<User> users = new ArrayList<>();

这里有一个带有 emdeded 的多对多示例：

    @Entity
    public class UserRoleMaster implements Serializable {

    @EmbeddedId
    private UserRoleMasterId id;

    @ManyToOne
    @JoinColumn(name = "user_master_id", referencedColumnName = "user_master_id", insertable = false, updatable = false)
    private UserMaster userMaster;

    @ManyToOne
    @JoinColumn(name = "user_roles_id", referencedColumnName = "user_roles_id", insertable = false, updatable = false)
    private UserRoles userRoles;

    //getter  //setter //constructures

       @Embeddable
       public static class UserRoleMasterId implements Serializable {

        @Column(name = "user_master_id")
        protected Long userMasterId;

        @Column(name = "user_roles_id")
        protected Long userRolesId;
       //constrcture //getter //setters
   }
 }