Spring Boot JPA One To Many and Many to One With Multiple Tables - spring-boot

Question

I have 5 Tables, A User can have many module/role/plant. user_master is the main table with user details and user_roles is the sub table with module/role/plant details. My doubt is how to write the relationship in Model Class.
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)
The remaining module/role/plant have their own masters, master_id are primary key to master tables.
I just want to write user_master and user_roles model class. One-to-many & many-to-one mapping is required.

Answer 1

For one to many, you can have like below in your entity class:
#OneToMany in user entity
#OneToMany(mappedBy = "user")
private List<Role> roles;
#ManyToOne at roles side
#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<>();
and role side:
#ManyToMany(mappedBy = "role")
private List<User> users = new ArrayList<>();
here is an example to have many to many with emdeded:
#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
}
}