one-to-one mapping.

[harshad kadam]

hello,
i am beginner to hibernate. please guide me with one to one mapping.

DB table structure:

EMPLOYEE_MASTER ( ID DECIMAL NOT NULL, USER_NAME VARCHAR(100) NOT NULL, PASSWORD VARCHAR(100) NOT NULL, FIRST_NAME VARCHAR(100) NOT NULL, LAST_NAME VARCHAR(100) NOT NULL, PRIMARY KEY (ID) )

EMPLOYEE_CONTACT ( ID DECIMAL DEFAULT '0' NOT NULL, EMPLOYEE_ID DECIMAL, MOBILE VARCHAR(15), HOME VARCHAR(15), WORK VARCHAR(15), FAX VARCHAR(15), EMAIL VARCHAR(50), PRIMARY KEY (ID), CONSTRAINT EC_UK_EMPLOYEE UNIQUE (EMPLOYEE_ID) )

Employee.java

private long id;
	private String userName;
	private String password;
	private String firstName;
	private String lastName;
	
	private EmployeeContact employeeContact;

EmployeeContact.java

private long id;
	private Employee employee;
	private String mobile;
	private String home;
	private String work;
	private String fax;
	private String email;

Employee.hbm.xml
<hibernate-mapping> <class name="com.test.hibtutorial.model.Employee" table="EMPLOYEE_MASTER"> <id name="id" type="long"> <column name="ID" /> <generator class="increment" /> </id> <property name="userName" type="java.lang.String"> <column name="USER_NAME" /> </property> <property name="password" type="java.lang.String"> <column name="PASSWORD" /> </property> <property name="firstName" type="java.lang.String"> <column name="FIRST_NAME" /> </property> <property name="lastName" type="java.lang.String"> <column name="LAST_NAME" /> </property> <one-to-one name="employeeContact" class="com.test.hibtutorial.model.EmployeeContact" property-ref="employee" cascade="all"></one-to-one> </class> </hibernate-mapping>

EmployeeContact.hbm.xml
<hibernate-mapping> <class name="com.test.hibtutorial.model.EmployeeContact" table="EMPLOYEE_CONTACT"> <id name="id" type="long"> <column name="ID" /> <generator class="increment" /> </id> [b]<one-to-one name="employee" class="com.test.hibtutorial.model.Employee" constrained="true"></one-to-one>[/b] <property name="mobile" type="java.lang.String"> <column name="MOBILE" /> </property> <property name="home" type="java.lang.String"> <column name="HOME" /> </property> <property name="work" type="java.lang.String"> <column name="WORK" /> </property> <property name="fax" type="java.lang.String"> <column name="FAX" /> </property> <property name="email" type="java.lang.String"> <column name="EMAIL" /> </property> </class> </hibernate-mapping>

Here in EmployeeBean.java, i construct employee object

                Employee employee = new Employee();
		
		employee.setUserName("harshadkadam");
		employee.setPassword("ferdelance");
		employee.setFirstName("harshad");
		employee.setLastName("kadam");

EmployeeContact employeeContact = new EmployeeContact();
		
		employeeContact.setEmail("[e-mail]");
		employeeContact.setFax("8811881188");
		employeeContact.setHome("1188118811");
		employeeContact.setMobile("8888111188");
		employeeContact.setWork("8888111188");
		
		employee.setEmployeeContact(employeeContact);

                EmployeeDaoImpl employeeDaoImpl = new EmployeeDaoImpl();
		
		long result = employeeDaoImpl.save(employee);

                

Here in EmployeeDaoImpl.java i save the employee object

public long save(Employee employee) {
		long result = 0;
		Session session = HibernateUtil.currentSession();
		try {
			session.beginTransaction();
			result = (Long) session.save(employee);
			session.getTransaction().commit();
		} catch (HibernateException e) {
			e.printStackTrace();
		} finally {
			session.flush();
			HibernateUtil.closeSession();
		}
		return result;
	}

The problem is one to one mapping. The EmployeeContact object gets saved except employee_id. EMPLOYEE_ID remains null in EMPLOYEE_CONTACT table. Please guide me where the configuration is fallen short.

[ntumba lobo]

why are you using "property-ref" in your Employee mapping ?
It is not necessary to establish the one-to-one relationship unless you work with legacy database.
It could be the problem.

[harshad kadam]

ntumba lobo wrote:why are you using "property-ref" in your Employee mapping ?
It is not necessary to establish the one-to-one relationship unless you work with legacy database.
It could be the problem.

I reffered "property-ref" from this tutorial.

As per your advice i removed "property-ref" but didn't work for me. Problem persists.