org.hibernate.QueryException：不是关联

Question

我想通过限制向Hibernate中的条件添加订单。 我有两个表Event和MainEvent，关系为One To Many（MainEvent有很多事件）。

    final Criteria criteria = getCurrentSession().createCriteria(
            Event.class);
    criteria.createAlias("mainEvent.date", "deadline");
    criteria.addOrder(Order.asc("deadline"));
    return criteria.list();

当我尝试运行它时，它会给我以下错误：

org.hibernate.QueryException：不是关联：date。

MainEvent实体：

@Entity
@Table(name = "MAIN_EVENT")
public class MainEventEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "MAIN_EVENT_ID")
    private int id;

    @Column(name = "MAIN_EVENT_DATE")
    private Date date;

    @OneToMany(mappedBy = "mainEvent", fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)
    private List<EventEntity> events = new ArrayList<EventEntity>();

}

事件实体：

@Entity
@Table(name = "EVENT")
public class EventEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "EVENT_ID")
    private int id;

    @ManyToOne(cascade = CascadeType.PERSIST)
    @JoinColumn(name = "MAIN_EVENT_ID", nullable = false)
    private MainEventEntity mainEvent;

}

Answer 1

根据Criteria.createAlias的API，您可以为关联创建别名 ，而不是关联字段。

createAlias

Criteria createAlias(String associationPath,
                     String alias)
                     throws HibernateException
Join an association, assigning an alias to the joined association.



Parameters:
associationPath - A dot-seperated property path
alias - The alias to assign to the joined association (for later reference).
Returns:
this (for method chaining)

Answer 2

   final Criteria criteria = getCurrentSession().createCriteria(
        Event.class);
criteria.createAlias("mainEvent", "me");
criteria.addOrder(Order.asc("me.deadline"));
return criteria.list();