Hibernate Criteria API相当于HQL select子句？

Question

我想对两个持久化类进行组合查询.

在HQL中,这可以通过select子句来实现,

select new Family(mother, mate, offspr)
    from DomesticCat as mother
        join mother.mate as mate
        left join mother.kittens as offspr

在上面的例子中,Family是一个以DemesticCat作为其construtor params的联合类

什么是HQL select子句的Criteria等价物？

Answer 1

你必须使用ResultTransformer这个.在Hibernate的3.2:变压器为HQL和SQL的博客文章给出了下面的例子(其中StudentDTO是一个非实体bean):

List resultWithAliasedBean = s.createCriteria(Enrolment.class)
  .createAlias("student", "st").createAlias("course", "co")
  .setProjection( Projections.projectionList()
                   .add( Projections.property("st.name"), "studentName" )
                   .add( Projections.property("co.description"), "courseDescription" )
          )
          .setResultTransformer( Transformers.aliasToBean(StudentDTO.class) )
          .list();

 StudentDTO dto = (StudentDTO)resultWithAliasedBean.get(0);