Java Hibernate 的 Transformers.aliasToBean() 方法
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Hibernate's Transformers.aliasToBean() method
提问by cometta
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?
User.class里面的属性employe不需要大写吗？
private String EMPLOYEENO;
//get/set for EMPLOYEENO
If I change the EMPLOYEENOto small letter, it doesn't work. Can anyone explain why the variable name must be all capital letters?
如果我将 更改EMPLOYEENO为小写字母，则不起作用。谁能解释为什么变量名必须全部大写？
采纳答案by Pascal Thivent
See the Hibernate 3.2: Transformers for HQL and SQLblog post:
请参阅Hibernate 3.2：HQL 和 SQL 转换器博客文章：
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 afuzzyAliasToBean()method ;)
SQL 转换器
使用本机 sql 返回非实体 bean 或 Map 通常比 basic 更有用
Object[]。现在可以使用结果转换器。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);提示：
addScalar()在 HSQLDB 上需要调用以使其匹配属性名称，因为它以全部大写形式返回列名称（例如“STUDENTNAME”）。这也可以通过搜索属性名称而不是使用精确匹配的自定义转换器来解决 - 也许我们应该提供一种fuzzyAliasToBean()方法;)
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().
也许您面临的情况与提示中描述的情况相同，在这种情况下，您应该尝试将调用添加到addScalar().
回答by Misha
Consider putting column aliases in double quotes. Oracle doesn't uppercase aliases specified in double quotes.
考虑将列别名放在双引号中。Oracle 不使用双引号指定的大写别名。
Query query = getHibernateTemplate().getSessionFactory().getCurrentSession().createSQLQuery(
"select proj_employee.employee_no \"employeeNo\", ...
.setResultTransformer(Transformers.aliasToBean(User.class))
;
;
