Spring data JPA @Query mapping with named columns

Question

I use Spring Boot 1.5 and spring data JPA with MySQL. I tried to run a simple counting query on a single table, but could not find a better way to map the Query results than thi

Answer 1

How about using Projections as below?

static interface VehicleStats { 
    public String getSourceModule();
    public Long getVehicleCount();
}

And your repository method would be

@Query("select v.sourceModule as sourceModule, count(v) as vehicleCount from Vehicle v group by v.sourceModule")
List<VehicleStats> sourceModuleStats();

In your Service class, you can use the interface methods as below.

List<VehicleStats> objects = vehicleRepository.sourceModuleStats();
return objects.stream()
        .map(o->SourceModuleStatDTO.from(getSourceModule(),getVehicleCount() )
        .collect(Collectors.toList());