jpql查询中列的别名

Question

I'm working in a Restful project with Spring Jpa so I'm using the @Query annotation. I was wondering how can I set aliases to the columns in my query? because the response displays every register of the resulset as an array 0,1,2 instead of that I want to display the custom name that I want to set with the alias.

here's some code

DaoGameI.java

public interface DaoGameI extends JpaRepository<Game, Integer> {

    @Query("SELECT g.id AS id_game, g.scoreHomeTeam As score_home_team, g.date AS game_date" 
           " FROM Game g "
          )
    public List<Game> allGames();

}

ServiceGame.java

@Autowired
    private DaoJuegoI iGames;

    @RequestMapping(value="/all")
    public @ResponseBody List<Game> all(){
        return iGame.allGames();
    }

then I get this response..

instead of OI want to display id_game . instead of 1 I want to display score_home_team . instead of 2 I want to display date

Hope someone can help me!

Answer 1

One way to achieve this is by defining a new object containing these three parameters:

    public class GameResponse{

        private Long id_game;

        private Long score_home_team;

        private Date game_date;

        //All getters and setters
        //Add a  default Constructor
        //And another parameterized constructor
        public GameResponse(Long id, Long score, Date date){
            this.id_game = id;
            this.score_home_team = score;
            this.game_date = date;
        } 
    }

Now modify your sql @Query as -

 @Query("SELECT NEW GameResponse(g.id, g.scoreHomeTeam, g.date) FROM Game g")
 public List<Game> allGames();

This solves your problem.