java - 使用 Hibernate 选择最常见的值

Question

@Entity
public class car {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id_car;
    @OneToOne
    private repair id_repair;
}

@Entity
public class repair {
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private int id_repair;
   @OneToOne
   @JoinColumn(name="id_car")
   private car id_car;
}

我编写了 sql 查询，这是我想要接收的内容

SELECT id_car,
       COUNT(*) AS c
FROM   repair
GROUP  BY id_car
ORDER  BY c DESC
LIMIT  5

如何使用 Hibernate 实现此目的？我想获取“id_car”和出现的次数。

Answer 1

List results = session.createCriteria(Car.class)
    .setProjection( Projections.projectionList()
        .add( Projections.rowCount(),"rCount")
        .add( Projections.groupProperty("id_car") )
    )
    .addOrder(Order.desc("rCount") )
    .setMaxResults(5)
    .list();