Hi folks.

In this moment I'm having a problem with my JPA implementation. I have two Entities as following:

Entity Position

package com.test; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; @Entity(name = "tbl_positions") public class Position implements Serializable { private static final long serialVersionUID = 1L; @Column(name = "posid") private long id; @Column(name = "posname") private String name; public long getId() { return id; public void setId(long id) { this.id = id; public String getName() { return name; public void setName(String name) { this.name = name;

Entity Employee

package com.test; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.OneToOne; @Entity(name = "tbl_employee") public class Employee implements Serializable { private static final long serialVersionUID = 1L; @Column(name = "empid") private long id; @Column(name = "empname") private String name; @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER) @JoinColumn(name = "emppositionid") private Position position; public long getId() { return id; public void setId(long id) { this.id = id; public String getName() { return name; public void setName(String name) { this.name = name; public Position getPosition() { return position; public void setPosition(Position position) { this.position = position;

In the other hand I have this Session Bean :

Remote Interface
package com.test; import javax.ejb.Remote; @Remote public interface EmployeeServiceRemote { public void createEmployee(Employee employee);

Remote Interface Implementation

package com.test; import javax.ejb.Stateless; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; @Stateless public class EmployeeServiceImpl implements EmployeeServiceRemote { @PersistenceContext(unitName = "MyPersistenceUnit") private EntityManager entityManager; public EmployeeServiceImpl() { public void createEmployee(Employee employee) { Sequence sequence = new Sequence(this.entityManager); long nextValue = sequence.getNextValue(SequenceName.EMPLOYEES); employee.setId(nextValue); this.entityManager.persist(employee);

The previous code includes the class Sequence . By the moment it only generates a secuential value for using as primary key for the entity Employee .

This is the content of the file persistence.xml

<?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> <persistence-unit name="MyPersistenceUnit"> <jta-data-source>java:/TESTDS</jta-data-source> <class>com.test.PositionEntity</class> <class>com.test.Employee</class> <properties> <property name="hibernate.show_sql" value="true"/> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> </properties> </persistence-unit> </persistence>

This is my test class :

package com.test; import javax.naming.Context; import org.junit.Before; import org.junit.Test; public class EmployeeTest { private static Employee getNewEmployee() { Position position = new Position(); position.setId(1); position.setName("ENGINEER"); Employee employee = new Employee(); employee.setName("Jhon Doe"); employee.setPosition(position); return employee; private static EmployeeServiceRemote lookUpService() throws Exception { EmployeeServiceRemote service = null; //Do lookup ... return service; @Test public void testCreateEmployee() throws Exception { Employee employee = getNewEmployee(); EmployeeServiceRemote service = lookUpService(); service.createEmployee(employee); System.out.println("Finish !");

And finally, this is the database script :
create table tbl_positions ( posid numeric(10) not null, posname varchar(255) not null, primary key(posid) create table tbl_employee ( empid numeric(10) not null, empname varchar(255) not null, emppositionid numeric(10) not null, primary key(empid) alter table tbl_employee add constraint fk_emp_pos foreign key (emppositionid) references tbl_positions (posid);

Before I executed test class EmployeeTest , I inserted one row in the table tbl_positions like this:
insert into tbl_positions (posid, posname) values (1, 'ENGINEER');

Because tbl_positions is a catalog and it most not be created when I create an Employee.

My problem arise when I executed the test class EmployeeTest . When I invoke the method service.createEmployee(employee) , I get the exception: Duplicate entry '1' for key 'PRIMARY' referencing the table tbl_positions . This is a problem for me because what I need is that if a Position already exists, it only creates the Employee . Even better, for business constraints when I create an Employee , all the Positions must exist.

Thanks for any help about it !!

Best tegards,
RADE