Lecture Notes 4ahif - NVS 21/22

package at.htl.carrental.control;

import at.htl.carrental.entity.Person;
import io.quarkus.runtime.StartupEvent;

import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.event.Observes;
import javax.inject.Inject;

@ApplicationScoped
public class InitBean {

    @Inject
    PersonRepository personRepository;

    void init(@Observes StartupEvent event) {
        Person p = new Person("Susi");
        personRepository.save(p);
    }

}

@Entity
@NamedQueries({
        @NamedQuery(
                name = "Person.findAll",
                query = "select p from Person p"
        )
})
public class Person {
    //...
}

@Test
void getAllPersons() {
    TypedQuery<Person> query = em
            .createNamedQuery("Person.findAll",Person.class);
    List<Person> persons = query.getResultList();
    assertThat(persons.size()).isEqualTo(8);
    logger.info(persons);
}

@Test
void getAllPersonsWithQuery() {
    TypedQuery<Person> query = em
            .createQuery("select p from Person p",Person.class);
    List<Person> persons = query.getResultList();
    assertThat(persons.size()).isEqualTo(8);
    logger.info(persons);
}

@Test
void getAllPersonsWithNativeQuery() {
    Query query = em
            .createNativeQuery("select p.id, p.name from person p");
    List<Object[]> persons = query.getResultList();
    for (Object[] elem : persons) {
        System.out.println(elem[0] + " " + elem[1]);
    }
    assertThat(persons.size()).isEqualTo(9);
}

package at.htl.carrental.entity;

import javax.persistence.*;

@Entity
@NamedQueries({
        @NamedQuery(
                name = "Person.countByInital",
                query = "select substring(p.name,1, 1), count(p) from Person p group by substring(p.name,1, 1)"
        )
})
public class Person {

    // ...
}

@ApplicationScoped
public class PersonRepository {

    @Inject
    EntityManager em;

    // ...

    public Map<Character, Integer> countByInitial() {
        Map<Character, Integer> result = new HashMap<>();
        Query query = em
                .createNamedQuery("Person.countByInital");
        List<Object[]> initials = query.getResultList();
        for (Object[] initial : initials) {
            result.put(
                    initial[0].toString().charAt(0),
                    Integer.parseInt(initial[1].toString())
            );
        }
        return result;
    }
}

@QuarkusTest
class PersonTest {

    // ...

    @Test
    void countLetters() {

        Query query = em.createQuery("select substring(p.name,1,1), count(p) from Person p group by substring(p.name,1,1)");
        List<Object[]> list = query.getResultList();

        for (Object[] elem : list) {
            logger.info(elem[0] + " - " + elem[1]);
        }

        assertThat(list.size()).isEqualTo(8);
    }
}