CODEWITHSUNDEEP
hibernate
mrjayviper
mrjayviper

Reputation: 2388

how do I save my data (one-to-many) using Hibernate?

I'm following this example: http://viralpatel.net/blogs/hibernate-one-to-many-xml-mapping-tutorial/

In the case of the example: it's a one-to-many relationship between departments vs employees (assuming employes can only work in 1 department).

In the example, the a new department is created every time and then new employees were attached to it.

what changes needs to happen if the department is already existing? like perhaps I ran the example again and want to add more employees to an existing department.

I searched the net but all examples/guides I came across assumes a new department is created every time.

My guess is that I need to setup a DAO function that searches the DB and returns a department datatype?

Thanks! :)

Here's the code as mentioned in viralpatel.net

public static void main(String[] args) {

    SessionFactory sf = HibernateUtil.getSessionFactory();
    Session session = sf.openSession();
    session.beginTransaction();

    Department department = new Department();
    department.setDepartmentName("Sales");
    session.save(department);

    Employee emp1 = new Employee("Nina", "Mayers", "1212");
    Employee emp2 = new Employee("Tony", "Almeida", "4343");

    emp1.setDepartment(department);
    emp2.setDepartment(department);

    session.save(emp1);
    session.save(emp2);

    session.getTransaction().commit();
    session.close();
}

Upvotes: 0

Views: 381

Answers (2)

Agung Setiawan
Agung Setiawan

Reputation: 1164

that was the same question i asked a while ago, you can add People to existing Department simply by load/get Department from database first

Department department = session.get(Department.class,new Long(10)); // i assume you are using Long for primary key

Employee emp1 = new Employee("Nina", "Mayers", "1212");
Employee emp2 = new Employee("Tony", "Almeida", "4343");

emp1.setDepartment(department);
emp2.setDepartment(department);

Upvotes: 1

William Seiti Mizuta
William Seiti Mizuta

Reputation: 7985

You can use the method get of the Session object to get the object from databse:

session.get(Department.class, id);

You can see the full documentation in the following ling: http://docs.jboss.org/hibernate/orm/3.5/api/org/hibernate/Session.html

Upvotes: 1

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