相关疑难解决方法(0)

我正在尝试使用HQL(Hibernate查询语言)在两个表之间创建一个联盟.此SQL脚本在我的SQL服务器上正常工作:

SELECT COUNT(DISTINCT linkedin_id) as test, school_name
FROM
(SELECT * FROM alum_education 
 UNION
 SELECT * FROM alum_connection_educations) AS UNIONS where school_name='some string'

问题是,当我尝试在这样的grails中运行它:

     def countOfEdu = AlumEducation.executeQuery("select count (distinct linkedinId ) as countOfEdu, schoolName as SchoolName from (SELECT * FROM alumEducation UNION SELECT * FROM alumConnectionEducations) AS UNIONS where schoolName='some string'" )

我收到此错误:

  org.hibernate.hql.ast.QuerySyntaxException: unexpected token: ( near line 1, column 83 [select count(distinct linkedinId )  as countOfEdu, schoolName as SchoolName  from (SELECT * FROM alumEducation UNION SELECT * FROM …

我有三个表:class,student,和teacher

table class
{
    class_id(PK)
}

table student
{
    student_id(PK)
    class_id(PK+FK)
}

table teacher
{
    teacher_id(PK)
    class_id(PK+FK)
}

我在SQL中有一个查询,工作正常.

SELECT data.class_id, count(data.class_id) AS count
FROM ((SELECT class_id FROM student)
        union all
        (SELECT class_id FROM teacher)) AS data
GROUP BY data.user_id
ORDER BY count desc

该查询包含from子句和union操作中的子查询.我无法将其转换为HQL.

请从上面的SQL查询中给我高效的HQL查询.

我有2个实体:EntityA和EntityB.

它们是无关的,我不能将它们放在继承树中,因为某些限制超出了本问题的范围.

但是我需要在同一个JPQL或HQL查询中获得包含两个实体的所有实例的混合List.这可能是JPA甚至直接使用Hibernate吗？

我需要这样的东西:

FROM EntityA WHERE fieldA=1
UNION
FROM EntityB WHERE fieldB="aa"

任何提示？

嗨,我想在HQL中排序

ORDER BY IF g.groupAdminId=:adminid THEN 1 ELSE 0 END ASC

但它不起作用,我希望拥有用户首先管理员的所有实体,我怎样才能实现这一目标？