I have a one-to-one relationship using PrimaryKeyJoinColumn
annotated on the parent side. And now I want to save the child entity by itself.
For example, I have Employee
and EmpInfo
as the child entity, I need to save EmpInfo
(of course after setting the id property of the parent to it). However, when such an arrangement is used, I get an exception listed below...
org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist
Any ideas why hibernate does not allow this? To be more clear, the code I have is below...
ParentEntity:
public class Employee {
private Long id;
private String name;
private EmployeeInfo info;
private Integer enumId;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public Long getId() {
return id;
}
@Column(name="EMP_NAME")
public String getName() {
return name;
}
@PrimaryKeyJoinColumn
@OneToOne(cascade = CascadeType.REMOVE)
public EmployeeInfo getInfo() {
return info;
}
}
ChildEntity:
@Table(name="EMP_INFO")
@Entity
public class EmployeeInfo {
private Long id;
private String email;
@Column(name="EMPLOYEE_EMAIL")
public String getEmail() {
return email;
}
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name = "emp_id", nullable = false)
public Long getId() {
return id;
}
}
The way I try to save it is...
Employee emp = new Employee();
emp.setEnumId(SimpleEnum.COMPLETE);
emp.setName("Shreyas");
EmployeeInfo info = new EmployeeInfo();
info.setEmail("Sh@gmail");
concreteDAO.save(emp); // This uses the JPATemplate provided by Spring JpaDaoSupport
info.setId(emp.getId());
concreteDAO.saveEmpInfo(info);
Any pointers would be much appreciated, as to how can I try to save the child entity?
The problem here is that the @Id
of EmployeeInfo
is declared as being auto-generated and you're thus not supposed to set it manually (Hibernate looks at the Entity passed to persist
and assumes it is already in the database because the @Id
field is populated).
In other words, remove the @GeneratedValue
on EmployeeInfo
if you want to set the PK manually.
Note that Hibernate provides support for OneToOne
association using a shared primary key in JPA 1.0 through a custom extension. See:
In JPA 2.0, derived identifiers are well supported and you can annotate OneToOne
and ManyToOne
associations with @Id
. See:
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