I have to entities modeled Session and Speaker, with ManyToMany relationship, and I wanted to delete an instance of Session, but in the DB it is the foreign key of another table. Below is the entity model
#Entity(name = "sessions")
public class Session {
// attributes do not respect camel case notations because they
// need to match table notations in order to auto bind without annotations
// otherwise that is done with #Column annotation
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long session_id;
private String session_name;
private String session_description;
private String session_length;
#OnDelete(action = OnDeleteAction.CASCADE)
#ManyToMany()
#JoinTable(
name = "session_speakers",
joinColumns = #JoinColumn(name = "session_id"),
inverseJoinColumns = #JoinColumn(name = "speaker_id")
)
private List<Speaker> speakers;
public Session() {
}
I tried to use OnDelete Cascade, but it still didn't work. (I did read that it is not advised to use on ManyToMany relationship)
#RequestMapping(value = "{id}", method = RequestMethod.DELETE)
public void delete(#PathVariable Long id){
sessionRepo.deleteById(id);
}
EDIT:
here is also the Speaker entity
#Entity(name = "speakers")
public class Speaker {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long speaker_id;
private String first_name;
private String last_name;
private String title;
private String company;
private String speaker_bio;
#Lob
#Type(type = "org.hibernate.type.BinaryType")
private Byte[] speaker_photo;
public Byte[] getSpeaker_photo() {
return speaker_photo;
}
public void setSpeaker_photo(Byte[] speaker_photo) {
this.speaker_photo = speaker_photo;
}
#ManyToMany(mappedBy = "speakers")
#JsonIgnore// added to resolve serialization issues
private List<Session> sessions;
Related
User.java
#Entity
#Table(name = "users")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "user_role_id", referencedColumnName = "id")
private UserRole userRole;
}
UserRole.java
#Data
#Entity
#Table(name = "user_roles")
public class UserRole implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
}
Client.java
#Data
#Entity
#Table(name = "clients")
public class Client implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumns({ #JoinColumn(name = "user_id", referencedColumnName = "id"),
#JoinColumn(name = "user_role_id", referencedColumnName = "user_role_id") })
private User user;
}
Error
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Unable to find column with logical name: user_role_id in users
In RDBMS, users.(id, user_role_id) is unique so clients table can refer to that.
Last time, I was using insertable = false, updatable = false on user_role_id, but when I want to add records of new client, I always need to add user_role_id manually user.setUserRoleId(userRole.getId()) after user.setUserRole(userRole) and I think that is bad practice of ORM (it should be added automatically when I set user.setUserRole(userRole))
#Column(name = "user_role_id", insertable = false, updatable = false)
private Integer userRoleId;
What should I do so the relation can be mapped in Spring JPA? and what is the best practice?
In other words, this is also mean how to reference to foreign key generated logical name column?
OK! Please try following configuration:
Below is a important code part and under this link you may find repository with working example
UserRole.java
#Data
#Entity
#Table(name = "user_roles")
public class UserRole implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "role_id")
private Integer roleId;
}
User.java
#Data
#Entity
#Table(name = "users")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "user_id")
private Integer userId;
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name = "user_role_id", referencedColumnName = "role_id")
private UserRole userRole;
}
Client.java
#Data
#Entity
#Table(name = "clients")
public class Client implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "client_id")
private Integer clientId;
#OneToOne(fetch = FetchType.LAZY)
#JoinColumns(
value = {
#JoinColumn(name = "client_role_id", referencedColumnName = "user_role_id"),
#JoinColumn(name = "client_user_id", referencedColumnName = "user_id"),
}
,
foreignKey = #ForeignKey(
name = "FK_user_with_role",
foreignKeyDefinition = "FOREIGN KEY (client_user_id, client_role_id)\n" +
" REFERENCES users \n" +
" (user_id, user_role_id) \n" +
" ON UPDATE CASCADE\n" +
" ON DELETE CASCADE")
)
private User user;
}
Please note that beside adding a foreignKey in the Client implementation, you MUST keep the sequence of #JoinColum annotations.. I don't know what is the reason behind, but if you flip those lines you'll still get your error as it was before :)
EDIT: I've added another answer which fits best in my opinion. I'm leaving this one as well to see the other steps I tried.
Though the solution is not elegant and not using JPA as requested. Just in case anything in here would be helpful
If I understand the main issue correctly - you want to bind Client entity with Role entity via User entity, by first setting User's Role and then transfer that "property" by using only UserId instead setting additionally RoleId while creating Client.
Basically after playing for a while with your model I think the main issue is to assign data to each other within a #Transactional methods. That seems to be caused ba Lazy fetch strategy.
My proposal for solution that binds all your Entities according expectations differs only from yours with ommiting the RoleId JoinColumn in Clients table. I have checked that when calling a service that would have #Transactional methods, you can assign a Role to the User and User to the Client with simple user.setRole(roleEntity) followed by client.setUser(userEntity).
All the data is then consistent. No need to call further like getters and setters as you mentioned in the second part of your question. Question is if for any reason you need to have RoleId as well in your Clients Table, then this soultion would have to be enhanced by additional column?
UserRole.java
#Entity
#Table(name = "user_roles")
public class UserRole implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "role_id")
private Integer roleId;
//getters and setters and toString
}
User.java
#Entity
#Table(name = "users")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "user_id")
private Integer userId;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "user_role_id", referencedColumnName = "role_id")
private UserRole userRole;;
//getters and setters and toString;
}
Client.java
#Entity
#Table(name = "clients")
public class Client implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "client_id")
private Integer clientId;
#OneToOne(fetch = FetchType.LAZY)
#JoinColumns({
#JoinColumn(name = "client_user_id", referencedColumnName = "user_id"),
})
private User user;
#Column(name = "client_role_id")
private Integer roleId;
#PrePersist
#PreUpdate
private void prePersist(){
try {
roleId = getUser().getUserRole().getRoleId();
} catch (NullPointerException e){
roleId = null;
}
}
//getters and setters and toString
}
UserService.java
#Service
public class UserService {
UserRepo userRepo;
public UserService(UserRepo userRepo) {
this.userRepo = userRepo;
}
#Transactional
public void save(User user) {
userRepo.save(user);
}
#Transactional
public User getReferenceById(int i) {
return userRepo.getReferenceById(i);
}
}
ClientService.java
#Service
public class ClientService {
private ClientRepo clientRepo;
private UserService userService;
public ClientService(ClientRepo clientRepo, UserService userService) {
this.clientRepo = clientRepo;
this.userService = userService;
}
#Transactional
public Client save(Client client){
return clientRepo.save(client);
}
#Transactional
public Client getReferenceById(int i) {
return clientRepo.getReferenceById(i);
}
#Transactional
public void printClient(Client client){
client = clientRepo.getReferenceById(client.getClientId());
System.out.println(client);
}
#Transactional
public void bindUserToClient(int userId, int clientId) {
Client entity = clientRepo.findById(clientId).orElseGet(Client::new);
entity.setUser(userService.getReferenceById(userId));
}
#Transactional
public void printClient(int i) {
clientRepo.findById(i).ifPresentOrElse(this::printClient, EntityNotFoundException::new);
}
}
This configuration after running this commandLineRunner:
#Configuration
public class Config {
#Bean
#Transactional
public CommandLineRunner commandLineRunner(
#Autowired UserRoleRepo roleRepo,
#Autowired UserService userService,
#Autowired ClientService clientService
) {
return args -> {
for (int i = 0; i < 5; i++) {
roleRepo.save(new UserRole());
}
for (int i = 5; i > 0; i--) {
User user = new User();
user.setUserRole(roleRepo.getReferenceById(i));
userService.save(user);
}
Client client = new Client();
client.setUser(userService.getReferenceById(2));
client = clientService.save(client);
clientService.printClient(client);
client = new Client();
client.setClientId(1);
clientService.printClient(client);
int userId = 5;
clientService.bindUserToClient(userId, 1);
clientService.printClient(1);
};
}
}
gave me correct output in the console:
Client{id=1, user=User{id=2, userRole=UserRole{id=4}}}
Client{id=1, user=User{id=2, userRole=UserRole{id=4}}}
Client{id=1, user=User{id=5, userRole=UserRole{id=1}}}
WORKAROUND
I tried to reach the goal by use of Spring JPA but could'nt.
The workaround that keeps the referential integrity was by creating a constrains through DB like below and add #PrePersist and #PreUpdate annotated method which is updating the client's roleId as intended.
create table clients
(
client_id integer not null,
client_user_id integer,
client_role_id integer,
primary key (client_id)
);
create table user_roles
(
role_id integer generated by default as identity,
primary key (role_id)
);
create table users
(
user_id integer generated by default as identity,
user_role_id integer,
primary key (user_id),
CONSTRAINT User_Role UNIQUE (user_id, user_role_id)
);
alter table users
add constraint FK_role_id foreign key (user_role_id) references user_roles (role_id);
alter table clients
add constraint FK_user_id foreign key (client_user_id, client_role_id) references users (user_id, user_role_id) on update cascade ;
Thanks to that I could for instance update userRole in user entity, and the change was reflected in the clients table as well without any further actions
i had scheme of user parking and detail parking.
user can park many times (one to many)
im trying to add detail parking object to my db, but i dont have idea how to add the fk from the user in the row of the table, its gave me null there.
(ignore from the logic of the model, i just want to understood the logic how can i the object with fk of ther entity)
this is my code:
#PostMapping("/parking")
public String saveCarParking(#ModelAttribute("user") parkingUsers parkingUsers) {
// parkingUsers[id, firstName, lastName, license]
parkingUsers p = new parkingUsers("jhon", "nash", "248651355");
parkingUsersService.saveParkingUser(p);
// parkingDetails[id, entryDate, entryTime, exitDate, exitTime, user_id(FK)]
parkingDetails d = new parkingDetails(LocalDate.now(), null, LocalDate.now(), null);
parkingDetailsService.saveParkingUser(d);
//how i connect parkingDetails object with fk of parkingUsers?
//it adding now row of parkingDetails but without the fk of user
return "redirect:/parkingList";
}
parking user entity:
#Entity
#Table(name ="users")
public class parkingUsers {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "first_name")
private String firstName;
#Column(name = "last_name")
private String lastName;
#Column(name = "license")
private String license;
#OneToMany(mappedBy = "parkingUsers", cascade = CascadeType.ALL, orphanRemoval = true)
private List<parkingDetails> parkingDetails = new ArrayList<parkingDetails>();
public parkingUsers() {
}
public parkingUsers(String firstName, String lastName, String license) {
this.firstName = firstName;
this.lastName = lastName;
this.license = license;
}
//setter gettrs and tostring...
entity class of details parking
#Entity
#Table(name ="details")
public class parkingDetails {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "entry_date")
private LocalDate entryDate;
#Column(name = "entry_time")
private LocalDateTime entryTime;
#Column(name = "exit_date")
private LocalDate exitDate;
#Column(name = "exit_time")
private LocalDateTime exitTime;
#ManyToOne
#JoinColumn(name="user_id")
private parkingUsers parkingUsers;
public parkingDetails() {}
public parkingDetails(LocalDate entryDate, LocalDateTime entryTime, LocalDate exitDate, LocalDateTime exitTime) {
this.entryDate = entryDate;
this.entryTime = entryTime;
this.exitDate = exitDate;
this.exitTime = exitTime;
}
//test
// public parkingDetails(LocalDate entryDate, LocalDateTime entryTime, LocalDate exitDate, LocalDateTime exitTime, int user_id ) {
// this.entryDate = entryDate;
// this.entryTime = entryTime;
// this.exitDate = exitDate;
// this.exitTime = exitTime;
// this.parkingUsers.setId(user_id);
// }
//setter gettrs and tostring...
In the ParkingDetails entity, you can have a setter for "parkingUsers" variable to set user object.
In your REST api's saveCarParking() method, before calling "parkingDetailsService.saveParkingUser(d);" you can pass the user object to ParkingDetails using setter created in ParkingDetails.
This should work. No need to explicitly extract the user_id from user's object to pass into ParkingDetails.
Adding one more parameter of type ‘parkingUsers‘ in the constructor of ‘ ParkingDetails’ to initialize user in parking class will also work.
(Apart, it is a good practice to start the class name with a capital letter e.g. instead of having class name as parkingDetails, it should be ParkingDetails.)
I use OneToOne in the spring data JPA and I want to delete a record from the Address table without touching the user. But I can't.
If I remove User, in this case Address is removed, that's good.
But how can you delete an Address without touching the User?
https://github.com/myTestPercon/TestCascade
User.Java
#Entity
#Table(name = "user", schema = "testCascade")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(mappedBy = "user", cascade = CascadeType.ALL)
private Address address;
// Getter and Setter ...
}
Address.java
#Entity
#Table(name = "address", schema = "testCascade")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
#OneToOne
#MapsId
#JoinColumn(name = "id")
private User user;
// Getter and Setter ...
}
DeleteController.java
#Controller
public class DeleteController {
#Autowired
ServiceJpa serviceJpa;
#GetMapping(value = "/deleteAddressById")
public String deleteAddressById () {
serviceJpa.deleteAddressById(4L);
return "redirect:/home";
}
}
You got your mapping wrong thats all is the problem .
try the below and see
User.java
#Entity
#Table(name = "user", schema = "testCascade")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name="foriegn key column in user table for address example.. address_id")
private Address address;
// Getter and Setter ...
}
Address.java
#Entity
#Table(name = "address", schema = "testCascade")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
//name of the address variable in your user class
#OneToOne(mappedBy="address",
cascade={CascadeType.DETACH, CascadeType.MERGE, CascadeType.PERSIST,
CascadeType.REFRESH})
private User user;
// Getter and Setter ...
}
In order to solve this problem, you need to read the hibernate Documentation Hibernate Example 162, Example 163, Example 164.
And also I recommend to look at this is Using #PrimaryKeyJoinColumn annotation in spring data jpa
This helped me in solving this problem.
And also you need to specify the parameter orphanRemoval = true
User.java
#Entity(name = "User")
#Table(name = "user", schema = "testother")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(mappedBy = "user", cascade = CascadeType.ALL, orphanRemoval = true)
private Address address;
public void addAddress(Address address) {
address.setUser( this );
this.address = address;
}
public void removeAddress() {
if ( address != null ) {
address.setUser( null );
this.address = null;
}
}
// Getter and Setter
}
Address.java
#Entity(name = "Address")
#Table(name = "address", schema = "testother")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
#OneToOne
#MapsId
#JoinColumn(name = "id")
private User user;
// Getter and Setter
}
DeleteController .java
#Controller
public class DeleteController {
#Autowired
ServiceJpa serviceJpa;
#GetMapping(value = "/deleteUser")
public String deleteUser () {
User user = serviceJpa.findUserById(2L).get();
user.removeAddress();
serviceJpa.saveUser(user);
return "/deleteUser";
}
}
Or make a custom SQL query.
#Repository
public interface DeleteAddress extends JpaRepository<Address, Long> {
#Modifying
#Query("delete from Address b where b.id=:id")
void deleteBooks(#Param("id") Long id);
}
public class Address {
#Id
private Long id;
#MapsId
#JoinColumn(name = "id")
private User user;
}
Rename #JoinColumn(name = "id") to #JoinColumn(name = "user_id")
You can't say that the column that will point to user will be the id of the Address
I have created two Entities namely Teacher and Detail, the code snippet is shown below
Teacher.java
#Entity
#Table(name = "teacher")
public class Teacher implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private long id;
#Column(name = "name")
private String name;
#Column(name = "age")
private int age;
#OneToOne(mappedBy = "teacher", cascade = CascadeType.ALL)
private Detail detail;
public Teacher() {
}
public Teacher(String name, int age) {
this.name = name;
this.age = age;
}
//getter and setter
}
Detail.java
#Entity
#Table(name = "detail")
public class Detail implements Serializable {
#Id
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "id")
private Teacher teacher;
#Column(name = "subjects")
private String subjects;
public Detail() {
}
public Detail(String subjects) {
this.subjects = subjects;
}
//getter and setter
}
I am trying to achieve one to one mapping with the shared primary key concept
but when i execute the controller, only Teacher table is updating with the value
try {
Teacher teacher=new Teacher("xyz",23);
Detail detail=new Detail("Java,c,c++");
teacher.setDetail(detail);
session.beginTransaction();
session.save(teacher);
session.getTransaction().commit();
model.addAttribute("added", "data inserted");
session.close();
}
After executing only Teacher table is updated with the specified values.Detail table is still showing empty
It does not work exactly like that. You still need the id field in your Detail, so add:
#Id
private long id;
to your Deatail class.
And - as comment suggests - replace the #Id annotation in field Teacher to #MapsId. This way the id of Teacher is mapped to the id of Detail BUT ONLY if you also set the teacher to the detail - you always need to set both sides of relationship - like:
teacher.setDetail(detail);
detail.setTeacher(teacher);
I have two entity types in Spring with a relationship:
#Entity
public class Domain {
public Domain() {}
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
private String name;
private String description;
private String image;
#OneToMany(cascade=CascadeType.ALL, targetEntity=Subdomain.class,fetch = FetchType.LAZY)
#JoinColumn(name="domain_id")
private Set<Subdomain> subdomain = new HashSet<>();
//Default getters and setters
}
And the type subdomain:
#Entity
public class Subdomain {
public Subdomain() {}
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
private String name;
#JsonIgnore
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "domain_id", nullable = false)
public Domain domain;
//Default getters and setters
}
This works perfect with a get request, the relation is fetched. But how does it works with post request? I would create a new subdomain with the relationship to an existing domain:
"domain_id": "2"
And this:
"domain_id": "http://localhost/subdomain/2"
But this doesn't work. What is the best way to solve this?
Could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement