The ORDER BY clause orders the objects returned by the query.
The ASC keyword (the default) specifies ascending order, and the DESC keyword indicates descending order.
Example
The Entity
@Entity
public class Employee {
@Id
@GeneratedValue
private long id;
private String name;
private int salary;
private String dept;
.............
}
Using Query
public class ExampleMain {
private static EntityManagerFactory entityManagerFactory =
Persistence.createEntityManagerFactory("example-unit");
public static void main(String[] args) {
try {
persistEmployees();
findEmployees();
} finally {
entityManagerFactory.close();
}
}
public static void persistEmployees() {
Employee employee1 = Employee.create("Diana", "IT", 3000);
Employee employee2 = Employee.create("Rose", "Admin", 4000);
Employee employee3 = Employee.create("Denise", "IT", 1500);
EntityManager em = entityManagerFactory.createEntityManager();
em.getTransaction().begin();
em.persist(employee1);
em.persist(employee2);
em.persist(employee3);
em.getTransaction().commit();
em.close();
}
private static void findEmployees() {
EntityManager em = entityManagerFactory.createEntityManager();
Query query = em.createQuery("SELECT e FROM Employee e ORDER BY e.salary");
List<Employee> resultList = query.getResultList();
resultList.forEach(System.out::println);
em.close();
}
} Employee{id=3, name='Denise', salary=1500, dept='IT'} Employee{id=1, name='Diana', salary=3000, dept='IT'} Employee{id=2, name='Rose', salary=4000, dept='Admin'}
DESC Example
public class ExampleMain2 {
private static EntityManagerFactory entityManagerFactory =
Persistence.createEntityManagerFactory("example-unit");
public static void main(String[] args) {
try {
persistEmployees();
findEmployees();
} finally {
entityManagerFactory.close();
}
}
public static void persistEmployees() {
Employee employee1 = Employee.create("Diana", "IT", 3000);
Employee employee2 = Employee.create("Rose", "Admin", 4000);
Employee employee3 = Employee.create("Denise", "IT", 1500);
EntityManager em = entityManagerFactory.createEntityManager();
em.getTransaction().begin();
em.persist(employee1);
em.persist(employee2);
em.persist(employee3);
em.getTransaction().commit();
em.close();
}
private static void findEmployees() {
EntityManager em = entityManagerFactory.createEntityManager();
Query query = em.createQuery("SELECT e FROM Employee e ORDER BY e.salary DESC");
List<Employee> resultList = query.getResultList();
resultList.forEach(System.out::println);
em.close();
}
} Employee{id=2, name='Rose', salary=4000, dept='Admin'} Employee{id=1, name='Diana', salary=3000, dept='IT'} Employee{id=3, name='Denise', salary=1500, dept='IT'}
Example ProjectDependencies and Technologies Used: - h2 1.4.197: H2 Database Engine.
- hibernate-core 5.2.13.Final: The core O/RM functionality as provided by Hibernate.
Implements javax.persistence:javax.persistence-api version 2.1 - JDK 1.8
- Maven 3.3.9
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