Question

我正在尝试通过子查询从B实体（有效负载）获取属性。但是，如果设置别名，则会出现以下错误：

org.hibernate.QueryException：不关联：有效负载

如果我删除别名，错误将变为：

org.hibernate.HibernateException：未知实体：null

重要信息：

类A是主要查询的类，并且类A与类C具有一对一关系。类C与类B具有一对多关系。

@Entity
@Table(name = "A")
public class A{
@OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
  @JoinColumn(name = "C_ID")
  private C c;
}
@Entity
@Table(name = "C")
public class C{
...
  @OneToMany(fetch = FetchType.LAZY, mappedBy = "entityC")
  @Cascade({CascadeType.ALL})
  List<B> bs;
}
@Entity
@Table(name = "B")
public class B{
...
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "C_ID")
  private C entityC;
}

查询如下：

Criteria query = sessionFactory.getCurrentSession().createCriteria(A.class,"a")   
final DetachedCriteria dc = DetachedCriteria.forClass(B.class, "b");
dc.add(Restrictions.isNotNull("b.payload"));
dc.addOrder(Order.asc("b.id"));
dc.add(Restrictions.eqProperty("b.entityC", "c"));
dc.add(Restrictions.sqlRestriction("LIMIT 1"));
dc.setProjection(Projections.property("b.entityC.id"));
query.add(Subqueries.propertyIn("c.id", dc));
...
query.createAlias("c", "c");

此查询的目的是安装一个ADTO，该ADTO具有B的有效负载的属性，如下例所示：

query.setProjection(Projections.projectionList()
.add(Projections.groupProperty("b.payload").as("payload"))
...
query.setResultTransformer(new AliasToBeanResultTransformer(ADTO.class));

Hibernate Criteria子查询-HibernateException：未知实体：null

0 个答案: