Hibernate的Transformers.aliasToBean（）方法 [英] Hibernate's Transformers.aliasToBean() method

问题描述

  Query query = getHibernateTemplate（）。getSessionFactory（）。getCurrentSession（）。createSQLQuery（
select proj_employee.employee_no as employeeNo，... 
 .setResultTransformer （Transformers.aliasToBean（User.class））; 
  

里面的User.class
是propertyNumbersNo需要大写字母？

  private String EMPLOYEENO; 
 // get / set for EMPLOYEENO 
  

如果我更改 EMPLOYEENO to 小写字母，它不起作用。任何人都可以解释为什么变量名必须全部是大写字母？

解决方案

请参阅 Hibernate 3.2：用于HQL和SQL的变换器博客文章： b
$ b

SQL变形金刚

使用本地sql返回非实体
beans o r Map通常更有用
，而不是基本的 Object [] 。
结果变换器现在可以
。
$ b $ pre $ 列表resultWithAliasedBean = s.createSQLQuery（
SELECT st.name as studentName，co.description as courseDescription+
FROM Enrollment 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）;


提示： addScalar（） HSQLDB需要
才能与
属性名匹配，因为它返回所有大写字母列中的
名（例如
STUDENTNAME）。这也可能是
使用自定义转换器解决的，
使用完全匹配搜索属性名称而不是
- 也许我们应该
提供一个 fuzzyAliasToBean（） 方法
;）

也许你面对的情况与在这种情况下，您应该尝试添加对 addScalar（）的调用。

 Query query =  getHibernateTemplate().getSessionFactory().getCurrentSession().createSQLQuery(
                 "select proj_employee.employee_no as employeeNo, ...
 .setResultTransformer(Transformers.aliasToBean(User.class));

Inside User.class does the property employeNo need to be in capital letter?

private String EMPLOYEENO; 
//get/set for EMPLOYEENO

If I change the EMPLOYEENO to small letter, it doesn't work. Can anyone explain why the variable name must be all capital letters?

解决方案

See the Hibernate 3.2: Transformers for HQL and SQL blog post:

SQL Transformers

With native sql returning non-entity beans or Map's is often more useful instead of basic Object[]. With result transformers that is now possible.

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);

Tip: the addScalar() calls were required on HSQLDB to make it match a property name since it returns column names in all uppercase (e.g. "STUDENTNAME"). This could also be solved with a custom transformer that search the property names instead of using exact match - maybe we should provide a fuzzyAliasToBean() method ;)

Maybe you are facing the same situation than the one described in the tip in which case you should try to add calls to addScalar().

这篇关于Hibernate的Transformers.aliasToBean（）方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！