Question

我有一名班级员工。它有一个主键ID和名为supervisorID的列。我想显示主管ID作为员工姓名，所以我必须联系回同一个表。我正在使用Spring Roo和Hibernate所以我需要创建一个HQL查询来执行此操作，但我无法弄清楚如何从SQL转换为HQL，下面是SQL查询的示例。

SELECT e.ID, e.name AS Employee, s.name AS Supervisor  
FROM employee e  
  INNER JOIN employee s  
  ON s.ID = e.supervisorID  
ORDER BY e.ID;

Answer 1

看起来你想要一个标量查询。

   List<Object[]> rows = getEntityManager().createQuery(
       "select e.id, e.name, s.name "
        + " from Employee e join fetch e.supervisor s "
        + " order by e.id").getResultList();

   for ( Object[] row: rows ) {
       // Construct an instance (or whatever) with the values
       Long id = (Long) row[0];
       String eName = (String) row[1];
       String sName = (String) row[2];
   }

HQL加入声明

1 个答案: