Question

我有5个表，一个用户可以有多个模块/角色/工厂。 user_master是具有用户详细信息的主表，而user_roles是具有模块/角色/工厂详细信息的子表。我的疑问是如何在模型类中编写关系。

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)

其余模块/角色/工厂具有其自己的主服务器，master_id是主表的主键。

我只想编写user_master和user_roles模型类。需要一对多和多对一映射。

Answer 1

对于一对多的实体类，您可以像下面这样：

@OneToMany

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

@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<>();

下面是一个示例，其中包含很多：

    @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
   }
 }

Spring Boot JPA与多表一对多和一对多

1 个答案: