Unidirectional @OneToOne mapping persist order

Hibernate ORM
1

Hi,
I’ve tried to upgrade from Hibernate 5.3.13.Final to 5.4.x, but i ran to the following problem, related to OneToOne unidirectional mapping:

I have two tables EMPLOYEES and EMP_DETAILS. The EMP_DETAILS is a child table of EMPLOYEES and has a foreign key to it. These are the CREATE SQL statements:

CREATE TABLE EMPLOYEES (

                           EMP_ID BIGINT NOT NULL,
                           NAME VARCHAR(252),
                           DEPARTMENT VARCHAR(128),
                           SALARY BIGINT,
                           PRIMARY KEY (EMP_ID)
);
CREATE TABLE EMP_DETAILS (

                             ED_ID BIGINT NOT NULL,
                             EMP_ID BIGINT,
                             ADDRESS VARCHAR(252),
                             GENDER VARCHAR(8),
                             BANK_ACCOUNT VARCHAR(128),
                             PRIMARY KEY (ED_ID),
                             FOREIGN KEY (EMP_ID) REFERENCES EMPLOYEES(EMP_ID)
);

These are the entities:

@Entity
@Table(name="EMPLOYEES")
public class Employee {
    @Id
    @Column(name="EMP_ID", unique = true, nullable = false)
    private Long empId;

    private String name;

    private String department;

    private Long salary;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "EMP_ID")
    private EmpDetails empDetails;

//getters and setters
}
@Entity
@Table(name="EMP_DETAILS")
@Data
public class EmpDetails {
    @Id
    @Column(name="ED_ID", unique = true, nullable = false)
    private Long edId;

    private String address;

    private String gender;

    @Column(name="BANK_ACCOUNT")
    private String bankAccount;

    @Column(name="EMP_ID")
    private Long empId;
//getters and setters
}

When I create an Employee object with its corresponding EmpDetails one and try to persist the Employee, an exception is getting thrown because hibernate tries to persist the child table (EMP_DETAILS) first:

Hibernate: insert into EMP_DETAILS (address, BANK_ACCOUNT, EMP_ID, gender, ED_ID) values (?, ?, ?, ?, ?)
ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - The INSERT statement conflicted with the FOREIGN KEY constraint "FK__EMP_DETAI__EMP_I__07E417F5". The conflict occurred in database "xxxx", table " EMPLOYEES", column 'EMP_ID'.

The behavior in Hibernate 5.3.13.Final is different. It persists the EMLOYEES and then tries to persist the EMP_DETAILS.

Hibernate: insert into EMPLOYEES (department, name, salary, EMP_ID) values (?, ?, ?, ?)
Hibernate: insert into EMP_DETAILS (address, BANK_ACCOUNT, EMP_ID, gender,  ED_ID) values (?, ?, ?, ?, ?)

Which behavior is the correct one? In 5.4.x or in 5.3.13.Final?