i'm getting null value in a child table as a foreign key of parent table using spring data rest or spring data jpa accosiation - spring-boot

Question

enter image description here In this image first address for empId 1 and last two records are empid 2 (empid 2 haveing to address)
file:///home/user/Pictures/fk.png
#Entity
#Table(name = "Employee")
public class Employee {
#Id
#GeneratedValue
private Integer id;
private String name;
private Integer sal;
#OneToMany(cascade = CascadeType.ALL,mappedBy="employee")
private List<Address> addresses;
//getter setter
Child entity
#Entity(name="Address")
public class Address {
#Id
#GeneratedValue
private Integer aid;
private String city;
private String state;
#ManyToOne
#JoinColumn(name="id")
private Employee employee;
//getter setter
Repository
#Repository
#RepositoryRestResource(path="employee")
public interface EmployeeRepo extends JpaRepository<Employee,Integer> {
}
Input from RestClient
{
"name":"rdhe",
"sal":"20000",
"addresses":[{
"city":"hyd",
"state":"ts"
}]
}
if i use spring data jpa then code will be
// jpa Repository
public interface EmployeeRepo extends JpaRepository<Employee,Integer> {
}
// EmployeeServer class
#Service
public class EmployeeService {
#Autowired
EmployeeRepo employeeRepo;
public void saveEmployee(Employee employee){
employeeRepo.save(employee);
}
}
// controller
#RestController
public class EmployeeController {
#Autowired
EmployeeService employeeService;
#PostMapping(path="/save")
public void saveEmp(#RequestBody Employee employee){
employeeService.saveEmployee(employee);
}
}
if i'll use spring-data-rest at that time no need to create employeeService and controller class

Answer 1

I was getting the same problem until JsonManagedReference came to my rescue.
Try changing your entities to include them like this:
In the Employee Entity:
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy ="employee")
#JsonManagedReference
private List<Address> addresses;
In the Address Entity:
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id", nullable = false, updatable = false, insertable =true)
#JsonBackReference
private Employee employee;
I was not able to find why it works this way, so please let me know if you come to know :)

Answer 2

It is probably due to the fact that your mentioning #JoinColumn(name="id"). The name attribute in #JoinColumn defines the name of the foreign key field in the child table. Since you are specifying foreign key column as id on hibernate, it could be the issue. Please update it to the same name(ie fk_empid) as specified in database, it should work...