JPA returning empty result list while DB returns row set

I am trying to run a query to fetch some statistic data from my database. And I'm using JPA. But I faced such a trouble: when I run JPQL query, the empty result set is returned. But when I run SQL, produced with JPA for that JPQL query, I got a single row of data.

Here's what I've got:

The Ticket entity

@Entity
@Table(name="tickets")
public class Ticket extends AbstractEntity {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @Embedded
    private Owner owner;

    @ManyToOne
    @JoinColumn(name="flightId")
    private Flight flight;

    private String status;

    public Ticket() {
        this.status = "AVAILABLE";
    }

The Flight entity

@Entity
@Table(name="flights")
public class Flight extends AbstractEntity {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    private String departure;
    private String destination;
    private Date date;
    private float ticketCost;

    @OneToMany(mappedBy="flight", fetch=FetchType.LAZY, cascade=CascadeType.ALL)
    private List<Ticket> tickets = new ArrayList<Ticket>();

The result row class

public class SoldReportRow {
    private String departure;
    private String destination;
    private DateTime date;
    private int ticketsSold;
    private float totalCost;

    public SoldReportRow(Date date, String departure, String destination, Long ticketsSold, Double totalCost) {
        this.departure = departure;
        this.destination = destination;
        this.ticketsSold = ticketsSold.intValue();
        this.totalCost = totalCost.floatValue();
        this.date = new DateTime(date);
    }

The JPQL

SELECT NEW entities.SoldReportRow(f.date, f.departure, f.destination, 
    COUNT(t.id), SUM(f.ticketCost)) 
FROM  Ticket t JOIN t.flight f  
WHERE t.status = 'SOLD' AND t.owner IS NOT NULL AND f.date BETWEEN ? and ? 
GROUP BY f.id

The generated SQL

SELECT t0.DATE, t0.DEPARTURE, t0.DESTINATION, COUNT(t1.ID), SUM(t0.TICKETCOST) 
FROM flights t0, tickets t1 
WHERE ((((t1.STATUS = ?) AND NOT ((((((t1.ADDRESS IS NULL) 
    AND (t1.EMAIL IS NULL)) AND (t1.NAME IS NULL)) AND (t1.OWNERFROM IS NULL)) 
    AND (t1.PHONE IS NULL)))) AND (t0.DATE BETWEEN ? AND ?)) 
    AND (t0.ID = t1.flightId)) GROUP BY t0.ID

So here is what I got when I run JPQL:

And here is what I got when I run the generated SQL:

UPD: the TicketDAO methods

// ...

protected static EntityManagerFactory factory;
protected static EntityManager em;

static {
    factory = Persistence.createEntityManagerFactory(UNIT_NAME);
}

// ...

public static List<SoldReportRow> soldReportByDate(String from, String to) {
    DateTimeFormatter dfTxt = DateTimeFormat.forPattern("dd/MM/yyyy");
    DateTimeFormatter dfSql = DateTimeFormat.forPattern("yyyy-MM-dd");

    String startDate = dfSql.print(dfTxt.parseDateTime(from));
    String endDate = dfSql.print(dfTxt.parseDateTime(to));

    String query = String.format(
            "SELECT NEW entities.SoldReportRow(f.date, f.departure, f.destination, COUNT(t.id), SUM(f.ticketCost)) FROM " +
            "Ticket t JOIN t.flight f " +
            "WHERE t.status = 'SOLD' AND t.owner IS NOT NULL AND f.date BETWEEN '%s' and '%s' " +
            "GROUP BY f.id",
            startDate, endDate
    );

    return TicketDAO.query(SoldReportRow.class, query);
}

public static <T> List<T> query(Class<T> entityClass, String query) {
    EntityManager entityManager = getEntityManager();
    TypedQuery<T> q = entityManager.createQuery(query, entityClass);
    List<T> entities = null;

    try {
        entities = q.getResultList();
    } finally {
        entityManager.close();
    }

    return entities;
}

public static EntityManager getEntityManager() {
    return factory.createEntityManager();
}

The question is, why does this happen and how to fix that?

Thanks!