I have a problem with the relationship oneToMany. I created tables in SQLite DB, this is my tables:
My CategoryModel:
#Entity
#Table(name = "Category")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class CategoryModel {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String category_name;
private String category_description;
private String image_path;
#JsonIgnore
#OneToMany( mappedBy = "category")
private Set<ProductModel> category;
My ProducCategory:
#Entity
#Table(name = "Product_Category")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class ProductModel {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.AUTO)
private Long product_id;
private Long category_id;
private String name;
private String description;
private int numberOfProduct;
private String image;
private int price;
#ManyToOne
#JoinColumn(name = "country_id", nullable = false)
private CategoryModel category;
I can get data from the Category table well but when I call data from the Product_Category table I have the error:
SQL error or missing database (no such column: productmod0_.country_id)
country_id does not exist anywhere in your tables.
What you want is : #JoinColumn(name = "category_id", nullable = false)
Related
I made 2 one-to-one relationships with 2 foreign keys, but I can't make a constraint or how could I make the 2 unique keys be a unique key in the new table?
#Table(name = "cart")
public class Cart {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", nullable = false)
private Long id;
private int quantity;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "product_id")
private Product products;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "user_id")
private User users;
}
#Entity
#Table(name = "Products")
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
private int quantity;
private Double price;
private String image;
It spells my 2 keys correctly, for example
user_id = 2 , product_id =2 would be ok
but if I enter another user_id=2, product_id=2 should not work, but for me it is entered in the database
You can use #PrimaryKeyJoinColumn in the #OneToOne relation:
#OneToOne(cascade = CascadeType.ALL)
#PrimaryKeyJoinColumn(name = "product_id", referencedColumnName = "id")
private Product products;
I have some trouble with joining tables using Spring Boot JPA
I need to do this kind of joining:
**book2user — book to user
id INT NOT NULL AUTO_INCREMENT
time DATETIME NOT NULL
type_id INT NOT NULL
book_id INT NOT NULL
user_id INT NOT NULL**
Here are my Entity classes:
#Entity
#Table(name = "user")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
private String hash;
private Date reg_time;
private Integer balance = 0;
private String name;
// getters and setters
public class Book {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#ManyToOne
#JoinColumn(name = "author_id", referencedColumnName = "id")
private Author author;
#ManyToOne
#JoinColumn(name = "genre_id", referencedColumnName = "id")
private Genre genre;
private String title;
private String slug;
private String description;
private String priceOld;
private String price;
private String image;
private boolean is_bestseller;
private Date pub_date;
// getters and setters
In order to do this kind of joining I should create another entity class ??
Something like this should work:
#Entity
#Table("book2user")
public class Book2User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private LocalDateTime time;
private Integer typeId;
#OneToOne
private Book book;
#OneToOne
#JoinColumn(name = "user_id") //optional, if the name of the table and field matches.
private User user;
}
Here I have two tables; both have IDs as primary keys. I want to know how to join these tables without foreign keys, based on their IDs. What should be the service implementation and what should be in the repository? How to write #Query with JOINS?
#Entity
#Table(name = "procedures")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class Procedure implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "ProcedureId")
private int id;
#Column(name = "ProcedureName")
private String name;
#Column(name = "ProcedureCode")
private String code;
#Column(name = "ProcedureDesc")
private String desc;
// getters and setters
}
#Entity
#Table(name = "cliniciandescriptor")
public class CPTClinicianDescriptor {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "Id")
private int id;
#Column(name = "ConceptId")
private int conceptId;
#Column(name = "CPTCode")
private String cptCode;
#Column(name = "ClinicianDescriptorId")
private int clinicianDescriptorId;
#Column(name = "ClinicianDescriptor")
private String clinicianDescriptor;
// getters and setters
}
You can use the JOIN on syntax like in SQL
For example
select p from Procedure p join CPTClinicianDescriptor c on c.id = p.id;
Read more about that topic here:
https://72.services/how-to-join-two-entities-without-mapped-relationship/
Considering it as One-to-One relation, you can use something like this.
#Entity
#Table(name = "procedures")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class Procedure implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "ProcedureId")
private int id;
#Column(name = "ProcedureName")
private String name;
#Column(name = "ProcedureCode")
private String code;
#OneToOne(optional = false)
#JoinColumn(name = "id", updatable = false, insertable = false)
private CPTClinicianDescriptor descriptor;
#Column(name = "ProcedureDesc")
private String desc;
// getters and setters
}
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
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;
}
I have an unidirectional OneToMany JPA entity mapping in my (Spring Framework + Spring Data + Hibernate JPA) project. Entity classes are like in the following code.(I have removed irrelevant class members for brevity).
#Entity
#Table(name = "employees")
class Employee{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
#OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
#JoinColumn(name = "employee_id")
private List<DepartmentAssignment> departmentAssignments = new ArrayList<>();
}
#Entity
#Table(name = "department_assignments")
class DepartmentAssignment{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
#NotNull
#Column(name = "employee_id")
private Integer employeeId;
#NotNull
#Column(name = "department_id")
private Integer departmentId;
}
#Entity
#Table(name = "departments")
class Department{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
}
And, in one of my service classes have a method to remove a DepartmentAssignment from an Employee like below.
public Employee deleteDepartmentAssignment(Integer empId, Integer deptAssignmentId) {
Employee employee = employeeRepository.findOne(empId);
if(employee != null) {
for ( DepartmentAssignment da : employee.getDepartmentAssignments()) {
if(da.getId().equals(deptAssignmentId)) {
employee.getDepartmentAssignments().remove(da);
employee = employeeRepository.save(employee);
break;
}
}
}
return employee;
}
However, calling above methods gives me an error: org.hibernate.exception.ConstraintViolationException ,and in the SQL log, I can see Column 'employee_id' cannot be null error for the last SQL statement of the transaction.
Can anybody tell me what I'm doing wrong here and how to get it fixed?
You don't need to add
#NotNull
#Column(name = "employee_id")
private Integer employeeId;
to the Employee, if you use #JoinColumn(name = "employee_id"). Try to remove it.
You can try the following, not sure why you use the plain id in the object. Thats not object relational mapping.
For more details see Hibernate triggering constraint violations using orphanRemoval
#Entity
#Table(name = "employees")
class Employee{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "employee", orphanRemoval = true)
private List<DepartmentAssignment> departmentAssignments = new ArrayList<>();
}
#Entity
#Table(name = "department_assignments")
class DepartmentAssignment{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#ManyToOne(optional=false)
private Employee employee;
#ManyToOne(optional=false)
private Department department;
}
#Entity
#Table(name = "departments")
class Department{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
}
You must look .hbm.xml file and you should mapping your Entity in this file and
you can look this example
http://www.mkyong.com/hibernate/hibernate-one-to-many-relationship-example/
I hope it will be useful for you.
try removing
cascade = CascadeType.ALL
but im not 100% sure..