hibernate3.2里的Transformers

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