java - 在自定义类上保存查询结果

Question

我想将查询结果保存在列表中。但是当我调试查看列表时，它充满了 Object[]，而不是 Conta 类。

这是我的查询和 Conta 类。

Query query = em.createQuery("SELECT p.data data, c.nome nomePedido, c.valor, g.nome nomeGarcom FROM Pedidos p\n"
            + "    JOIN Cardapio c ON p.idItem = c.id\n"
            + "    JOIN Garcons g ON p.idGarcon = g.id", Conta.class);
    contaList = query.getResultList();



public class Conta {
private Date data;
private String nomeGarcom;
private String nomePedido;
private float valor;

public Conta(Date data, String nomePedido, float valor, String nomeGarcom) {
    this.data = data;
    this.nomeGarcom = nomeGarcom;
    this.nomePedido = nomePedido;
    this.valor = valor;
}  ... getters and setters

Answer 1

AFAIK，您可以在 JPA 中使用构造函数表达式，特别是因为已经有一个匹配的构造函数:

Query query = em.createQuery("SELECT new com.mine.Conta(p.data, g.nome, c.nome, c.valor) FROM Pedidos p\n" ...