How do you work with databases? Have you had any interesting tasks?

In working with databases in Java, I usually use ORM frameworks such as Hibernate or JPA, which allow abstraction from specific SQL and work with objects. For simple tasks — JDBC with prepared statements to avoid SQL injections.

Interesting tasks involved optimizing queries and data migrations. For example, I had to implement a complex batch processor to update millions of records with minimal impact on database performance. I used pagination and transactions with isolation control to avoid locks.

An example of a simple query with JPA:

@Entity
public class User {
    @Id
    private Long id;
    private String name;
    // getters and setters
}

// In the service
TypedQuery<User> query = entityManager.createQuery("SELECT u FROM User u WHERE u.name = :name", User.class);
query.setParameter("name", "Ivan");
List<User> users = query.getResultList();