Spring JPA: How to insert data to join many tables with #ManytoMany relationship - spring

Question

I'm starting to learn Spring Java Framework . I created some Enity to join 2 Model like my Database. And now I want to insert to Join Table by JpaRepository. What i have to do?
This is my Code (Please fix help me me if something is not right)
Model Users_RoomId to define Composite Primary Key
#Embeddable
public class Users_RoomId implements Serializable {
private static final long serialVersionUID = 1L;
#Column(name = "ID_room", nullable = false)
private String idRoom;
#Column(name = "user_id", nullable = false)
private int idUser;
}
Model Users_Room to join 2 Model Users and Room
#Entity
#Table(name ="bookroom")
public class Users_Room {
#EmbeddedId
private Users_RoomId usersroomId;
#ManyToOne
#MapsId("idRoom")
private Room room;
#ManyToOne
#MapsId("idUser")
private Users users;
#Column(name = "Bookday")
private String bookday;
Model Users and Room I used annotation #OneToMany
Model Users
#Entity
#Table(name = "users")
public class Users implements Serializable{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "user_id", nullable = false)
private int id;
#Column(name = "name", nullable = false)
private String name;
#Column(name = "email")
private String email;
#Column(name = "pass")
private String pass;
#Column(name = "role")
private int role;
#OneToMany(mappedBy = "users")
private List<Users_Room> user;
Model Room
#Entity
#Table(name ="room")
public class Room implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "ID_room", nullable = false)
private String id;
#Column(name = "name_room", nullable = false)
private String name;
#Column(name = "Description")
private String describe;
#ManyToOne
#JoinColumn(name = "ID_status")
private Status status;
#Column(name = "room_image")
private String image;
public Room() {
super();
}
#ManyToOne
#JoinColumn(name = "ID_kind")
private KindRoom kind;
#OneToMany(mappedBy = "room")
private List<Users_Room> rooms;
This is my database
So I don't know how to insert a new bookroom with iduser,idroom and bookday with JPA repository.. It'necessary to write Query in JPARepository or We just need to use method save() to insert data
Thanks everyone

Answer 1

I had same problem and solved with following code. I used method save() to insert data. Following code is 'createRoom' method in 'RoomService.java'.
RoomService.java
private final RoomRepository roomRepository;
private final UserRoomRepository userRoomRepository;
private final UserRepository userRepository;
public RoomService(RoomRepository roomRepository, UserRoomRepository userRoomRepository, UserRepository userRepository) {
this.roomRepository = roomRepository;
this.userRoomRepository = userRoomRepository;
this.userRepository = userRepository;
}
#Transactional
public RoomDto createRoom(Long userId, Long chattingUserId) {
Room room = roomRepository.save(new Room());
room.addUserRoom(userRepository.findById(userId).orElseThrow(()->new NoSuchElementException("No User")));
room.addUserRoom(userRepository.findById(chattingUserId).orElseThrow(()->new NoSuchElementException("No User")));
userRoomRepository.save(new UserRoom(userRepository.findById(userId).orElseThrow(()->new NoSuchElementException("No User")),room));
userRoomRepository.save(new UserRoom(userRepository.findById(chattingUserId).orElseThrow(()->new NoSuchElementException("No User")),room));
RoomDto roomDto = RoomDto.of(room);
return roomDto;
}