HQL不支持UNION
javax.servlet.ServletException: unexpected token: ( near line 1, column 1 [( select emp from com.neusoft.talentbase.common.business.organization.model.assignedjob.AssignedJobPO a,com.neusoft.talentbase.common.business.staffing.common.po.EmployeePO emp where a.oid=emp.jobID and a.leaderLevel in ('0','1') and a.unitPO.oid=1738419 and a.status='1' and emp.status='1' and emp.employeeStatus in ('2','5','11','7') ) union ( select e from com.neusoft.talentbase.common.business.organization.model.assignedjob.AssignedJobPO a,com.neusoft.talentbase.common.business.staffing.common.po.EmployeePO e,com.neusoft.talentbase.staffing.model.parttime.ParttimePO p where a.oid=p.jobID and e.oid=p.employee and a.leaderLevel in ('0','1') and a.unitPO.oid= 1738419 and a.status='1' and e.status='1' and p.status='1' and e.employeeStatus in ('2','5','11','7') )]
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:516)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:423)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
com.neusoft.talentbase.framework.core.strutsextension.TbRequestProcessor.process(TbRequestProcessor.java:80)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.neusoft.report.sample.security.LoginUserFilter.doFilter(LoginUserFilter.java:49)
com.neusoft.talentbase.framework.core.usercontext.UserContextFilter.doFilter(UserContextFilter.java:82)
com.neusoft.talentbase.framework.core.filter.CharsetEncodingFilter.doFilter(CharsetEncodingFilter.java:55)
HQL语句：
( select emp from AssignedJobPO a,EmployeePO emp where a.oid=emp.jobID and a.leaderLevel in ('0','1') and a.unitPO.oid=1738419 and a.status='1' and emp.status='1' and emp.employeeStatus in ('2','5','11','7') )
union
( select e from AssignedJobPO a,EmployeePO e,ParttimePO p where a.oid=p.jobID and e.oid=p.employee and a.leaderLevel in ('0','1') and a.unitPO.oid= 1738419 and a.status='1' and e.status='1' and p.status='1' and e.employeeStatus in ('2','5','11','7') )
原来HQL不支持UNION操作，因此会报错。
推荐 1，用视图，2，用两个简单的查询。
下面是stackoverflow上面的一个人的留言：
You could use id in (select id from ...) or id in (select id from ...)
e.g. instead of non-working
from Person p where p.name="Joe" union from Person p join p.children c where c.name="Joe" you could do
from Person p where p.id in (select p1.id from Person p1 where p1.name="Joe") or p.id in (select p2.id from Person p2 join p2.children c where c.name="Joe"); At least using MySQL, you will run into performance problems with the later though. It's sometimes easier to do a poor man's join on two queries instead:
// use set for uniqueness Set<Person> people = new HashSet<Person>((List<Person>) query1.list()); people.addAll((List<Person>) query2.list()); return new ArrayList<Person>(people); It's often better to do two simple queries than one complex one.
EDIT:
to give an example, here is the EXPLAIN output of the resulting MySQL query from the subselect solution:
mysql> explain select p.* from PERSON p where p.id in (select p1.id from PERSON p1 where p1.name = "Joe") or p.id in (select p2.id from PERSON p2 join CHILDREN c on p2.id = c.parent where c.name="Joe") \G *************************** 1. row *************************** id: 1 select_type: PRIMARY table: a type: ALL possible_keys: NULL key: NULL key_len: NULL ref: NULL rows: 247554 Extra: Using where *************************** 2. row *************************** id: 3 select_type: DEPENDENT SUBQUERY table: NULL type: NULL possible_keys: NULL key: NULL key_len: NULL ref: NULL rows: NULL Extra: Impossible WHERE noticed after reading const tables *************************** 3. row *************************** id: 2 select_type: DEPENDENT SUBQUERY table: a1 type: unique_subquery possible_keys: PRIMARY,name,sortname key: PRIMARY key_len: 4 ref: func rows: 1 Extra: Using where 3 rows in set (0.00 sec) Most importantly, 1. row doesn't use any index and considers 200k+ rows. Bad! Execution of this query took 0.7s wheres both subqueries are in the milliseconds.