Entity mapping to DTO - spring-boot

Question

I want to map query result to DTO of the following JPQL:
#Repository
public interface FooRepository extends JpaRepository<Foo, Id> {
#Query("select f.game, sum(f.timeSpent) as duration from foo f group by f.game order by duration desc")
List<Foo> findMostPlayable();
}
As a result, I receive list of objects which consist of GameCatalog object and Long number:
0 = {Object[2]#10670}
0 = {GameCatalog#10675}
1 = {Long#10676} 8968
Foo.class looks like:
#Entity
#Getter
#Setter
public class Foo{
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#ManyToOne(optional = false)
#JoinColumn(name = "game_catalog_id", nullable = false)
private GameCatalog game;
private Long timeSpent;
}
I plan to use MapStruct to map model with DTO but I cannot do that since 'findMostPlayable' returns result in such a way above.
How I can implement mapping here?
And should I use JPA JPQL way or hibernate features like projections and so on?

Answer 1

To get result of query with aggregate function,you can create your own class instead of using entity and use that.
Ex.
public class MyFoo {
private String game;
private int duration;
public String getGame() {
return game;
}
public void setGame(String game) {
this.game = game;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
}
#Repository
public interface FooRepository extends JpaRepository<Foo, Id> {
#Query("select new MyFoo(f.game as game, sum(f.timeSpent) as duration ) from foo f group by f.game order by duration desc")
List<MyFoo> findMostPlayable();
}