HQL内部联接查询在ManyToOne集合成员中排除对象

Question

I have a Translations class eg:

 class Translation{
      String key;
      String type;
      String userId;
      @OneToMany
      Set<TranslationValue> translations;
 }

which holds a OneToMany relationship with a TranslationValue class eg:

 class TranslationValue{
      String language;
      String value;
      @ManyToOne
      Translation translation;
 }

I would like to query based on the TranslationValue.language member and return a list of Translation objects which contain a set with only 1 TranslationValue object -> the one which was used as query parameter eg:

translationDao.findAllForLanguage("en");

This would return every translation object in the db that has TranslationValue.language = "en" and furthermore would remove from each object Translation.translations where language is not "en".

So far I'm returning a list of all Translation objects which have a TranslationValue object with a language="en" member in their respective translations Sets. I need to remove all TranslationValue objects that don't have language="en" though.

EDIT: progress

This query returns the correct amount of hits, but all values are null. ->

 @Override
public List<Translation> findAllForLanguage2(String language) {
    //TODO:finish
    final Query query = entityManager.createQuery(
            "select new " + getDomain().getSimpleName() + "(t.key,t.clientName,t.userId,t.type,t.platform,tv) from " + getDomain().getSimpleName() + " t right join t.translations tv where tv = some(from tv where tv.language = :language)");
    query.setParameter("language", language);


    return query.getResultList();
}

printing all from query
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}
translation: Translation{key='null', clientName='null', userId='null', type=null, platform='null', translations=null}

This query returns a Object [], where the second object is actually the TranslationValue object I want, but the Translation object is null ->

    @Override
public List<Object> findAllForLanguage(String language) {
    //TODO:finish
    final Query query = entityManager.createQuery(
            "from " + getDomain().getSimpleName() + " t full join t.translations tv where tv = some(from tv where tv.language = :language))");
    query.setParameter("language", language);


    return query.getResultList();
}

printing all from query
null
TranslationValue{language='en', value='feed'}
null
TranslationValue{language='en', value='feed'}
null
TranslationValue{language='en', value='broken'}
null
TranslationValue{language='en', value='broken'}
null
TranslationValue{language='en', value='water'}
null
TranslationValue{language='en', value='broken'}

Answer 1

This query should do fine

select t from Translation t join t.translations tv 
where tv.language = :language 
and size(t.translations) = 1