hibernate - How to do a Union SQL statement in HQL?

Question

I'm trying to create a Union between two tables, using HQL (Hibernate Query Language). This SQL script works fine on my SQL server:

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'

the problem is, when i try to run it in grails like this:

     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'" )

i get this error:

  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 alumConnectionEducations) AS UNIONS where schoolName='Duquesne University']

How can I run the above SQL statement in grails?

thanks jason

Answer 1

Unions are not supported by HQL. There is an issue in Hibernate's JIRA that is open since 2005.