# Task 

This task should be quite simple for you.

Your task is to implement the `updateDepartment()` method in the `DepartmentDaoImpl` class and also implement the `updateDepartment()` and `updateDepartmentLocation()` methods in the `DepartmentServiceImpl` class. After completing the task, run the code in the `Main` class, where the code for testing is already written. There, you can verify the functionality of your methods.

[Link to the Task](https://github.com/Codefinity-Java/Department_Layers_Improvement_Task) 

Use the same algorithm of actions that was used in the previous chapter. It won't differ at all here.

Hint

```
@Override
public Department updateDepartment(int departmentId, Department newDepartment) {
    Session session = null;
    Transaction transaction = null;
    Department department = null;

    if (newDepartment == null) {
        throw new NullPointerException("Department is null!");
    }

    try {
        session = sessionFactory.openSession();
        transaction = session.beginTransaction();

        department = getById(departmentId);
        department.setName(newDepartment.getName());
        department.setLocation(newDepartment.getLocation());

        session.merge(department);
        transaction.commit();

    } catch (Exception e) {
        if (transaction != null) {
            transaction.rollback();
        }
    } finally {
        if (session != null) {
            session.close();
        }
    }
    return department;
}

//DepartmentServiceImpl
@Override
public Department updateDepartment(int departmentId, Department newDepartment) {
    return departmentDao.updateDepartment(departmentId, newDepartment);
}

@Override
public Department updateDepartmentLocation(int departmentId, String newLocation) {
    Department department = getById(departmentId);
    department.setLocation(newLocation);
    updateDepartment(departmentId, department);
    return department;
}

Solution

Every backend developer must be proficient in working with various databases. Connecting a database to the code and performing data operations directly from Java code to execute SQL queries and various data operations directly from the code. JDBC and Hibernate help developers with this. It's time to learn how to connect a database to your IDE, use tables from this database, and manipulate data!

Why do we need a database? How does the interaction between a database and code work? What tools are used for different types of databases? You will learn all about this in this section!

This section will tell you how to set up and use Hibernate. You will learn how this framework works, what ORM is, and how to work with databases efficiently. You will also learn to write basic operations with a connected database, demonstrating your skills in practice!

In this section, we will complete work on the project's foundation for employee management in the company. We will add the remaining operations and one more entity.

Challenge: Department Layers Improvement

Task