Using COUNT in JPQL Query - jpa

Question

I have the following JPQL query:
List<DestinationInfo> destinations = em.createQuery("SELECT NEW com.realdolmen.patuva.dto.DestinationInfo(d.name, d.continent, MIN(t.departureDate), MIN(t.pricePerDay), COUNT(t.id))" +
" FROM Destination d, Trip t" +
" WHERE d.continent = :continent " +
" GROUP BY d.name, d.continent").setParameter("continent", searchedContinent).getResultList();
If I run this I get the error:
javax.ejb.EJBTransactionRolledbackException: org.hibernate.hql.internal.ast.QuerySyntaxException: Unable to locate appropriate constructor on class [com.realdolmen.patuva.dto.DestinationsList]
If I leave out the COUNT(t.id) and remove that parameter from my DestinationInfo constructor it works fine. Why can't I map the COUNT(t.id) to my DestinationInfo DTO.
This is my DestinationInfo class:
public class DestinationInfo {
private String name;
private Continent continent;
private Date earliestDeparture;
private Integer totalNumTrips;
private BigDecimal lowestPrice;
public DestinationInfo(String name, Continent continent, Date earliestDeparture, BigDecimal lowestPrice, Integer totalNumTrips) {
this.name = name;
this.continent = continent;
this.earliestDeparture = earliestDeparture;
this.totalNumTrips = totalNumTrips;
this.lowestPrice = lowestPrice;
}
// getters and setters
}

Answer 1

Apparently COUNT(t.id) returns a number of type long. Changing the DestinationInfo class to the following makes it work:
public class DestinationInfo {
private String name;
private Continent continent;
private Date earliestDeparture;
private long totalNumTrips;
private BigDecimal lowestPrice;
public DestinationInfo(String name, Continent continent, Date earliestDeparture, BigDecimal lowestPrice, long totalNumTrips) {
this.name = name;
this.continent = continent;
this.earliestDeparture = earliestDeparture;
this.totalNumTrips = totalNumTrips;
this.lowestPrice = lowestPrice;
}
// getters and setters
}