java - Select multiple items based on multiple IDs with hibernate -

i using hibernate in eclipse.

and have 3 1 many relation tables.

one [company] --> many [officer], , 1 [officer] --> many [task].

they have unique id (companyid, officerid, taskid).

currently know how find tasks belong officer , know how find officers belong company.

here code snippet:

public static arraylist<officer> getofficersbycompany(company company){     arraylist<officer> officers = new arraylist<officer>();     detachedcriteria detachedcriteria = detachedcriteria.forclass(officer.class);      detachedcriteria.add(restrictions.eq(key.company, company));     detachedcriteria.add(restrictions.eq(key.objstatus, value.actived));      list<object> list = hibernateutil.detachedcriteriareturnlist(detachedcriteria);      for(object o : list){         officers.add((officer) o);     }     return officers; } 

and below detachedcriteriareturnlist method in hibernateutil class.

public static list<object> detachedcriteriareturnlist(detachedcriteria dc){     session session = getsessionfactory().opensession();     session.begintransaction();     criteria criteria = dc.getexecutablecriteria(session);     list<object> list = criteria.list();     session.gettransaction().commit();     session.close();     return list; } 

however, if try all task belongs company, how should implement code. have tried using: detachedcriteria.add(restrictions.alleq(officers));

public static arraylist<task> gettasksbyofficers(map<string, object> officers){     arraylist<task> tasks = new arraylist<task>();      detachedcriteria detachedcriteria = detachedcriteria.forclass(task.class);      detachedcriteria.add(restrictions.alleq(officers));     list<object> list = hibernateutil.detachedcriteriareturnlist(detachedcriteria);      for(object o : list){         tasks.add((task) o);     }      return tasks; } 

but realise map stores unique key , value pair, if try use second officer's id first 1 replaced.

or there other ways perform selection faster , more efficient?

one [company] --> many [officer], , 1 [officer] --> many [task].

in hql should pretty straight forward (i gave using criteria api, did not allow joining same object class twice):

obviously, did not test queries, should work...

select task    task join task.officer o join o.company c  c.name = 'xxx' 

or

select t   company c join c.officers o join o.tasks t   c.name = 'xxx' 

note: experience criteria limited, have said. looking @ code, have 2 comments. maybe should not use map of officers list officers.values() alleq(). second remark: if didn't mistake, hibernate magically finds reference property want alleq with, otherwise, alleq misses property want compare to.

update: ok, promised, checked javadocs you: https://docs.jboss.org/hibernate/orm/3.5/api/org/hibernate/criteria.html

a join in hql equivalent of criteria added criteria or alias:

detachedcriteria = detachedcriteria.forclass(task.class)                    .createcriteria("officer") // officer property of task                    .createcriteria("company") // company property of officer                    .add(restriction.eq(key.company, compkey); // company  list<object> list = detachedcriteria                     .getexecutablecriteria(hibernatesession)                     .list(); 

this should going...

note on hql:

to run query, query hibernate session hql , call list() or executeupdate()on it. taskhqlstring hql-statement above. replace companykey in query named parameter :companykey:

string taskhqlstring = "select task "                        + "  task join task.officer o "                      + "            join o.company c "                      + " c.name = :companykey";  list<task> list = (list<task>)hibernatesession                   .createquery(taskhqlstring)                   .setparameter("companykey", companykeyvalue)                   .list();