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hibernate3.2里的Transformers

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hibernate 里想将sql的结果转为对象,但是对象不想再.hb.xml里定义,可以考虑用 ResultTransformer

使用SQL Transformers
    List resultWithAliasedBean = s.createSQLQuery("SELECT st.name as studentName, co.description as courseDescription " +"FROM Enrolment e " +"INNER JOIN Student st on e.studentId=st.studentId " +"INNER JOIN Course co on e.courseCode=co.courseCode")
      .addScalar("studentName")
      .addScalar("courseDescription")
      .setResultTransformer( Transformers.aliasToBean(StudentDTO.class))
      .list();
    StudentDTO dto =(StudentDTO) resultWithAliasedBean.get(0);


注意,如果不加上addScalar()调用的话,可能有些属性不会被设置值,因为他们可能是用大写字母返回的。

用Map

指定Transformers.ALIAS_TO_MAP就可以了,如下所示,你不必为了在需要记忆字段对应的位置,因为他们是map

    List iter = s.createQuery("select e.student.name as studentName," +"       e.course.description as courseDescription" +"from   Enrolment as e")
      .setResultTransformer( Transformers.ALIAS_TO_MAP )
      .iterate();
    String name = (Map)(iter.next()).get("studentName");


原文:http://swik.net/Hibernate/Hibernate+GroupBlog/Hibernate+3.2:+Transformers+for+HQL+and+SQL/cmxs

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