ignoring specific instances in search results

jeremycod · **Joined:** Mon Jul 16, 2012 1:11 pm **Posts:** 12

Hi,

I created a search box that returns 3 instances of Hibernate classes based on the current input so user can choose one of the selected instances. This works fine, but I want to exclude already selected instances from the search results. So basicaly, this method should receive a List<Comeptence> containing instances that should be ignored from search results. Do you have any proposal how this could be integrated in the query?

Thanks,
Zoran

Code:

   public Collection<Competence> getCompetencesByName(String searchString) {
      searchString=searchString.toLowerCase();
      Session session = persistence.currentManager();
      FullTextSession fullTextSession=Search.getFullTextSession(session);
      QueryBuilder qBuilder=fullTextSession.getSearchFactory().buildQueryBuilder().forEntity(Competence.class).get();
      Query query=qBuilder.keyword().wildcard().onField("title").matching(searchString+"*").createQuery();
      org.hibernate.Query hibQuery=fullTextSession.createFullTextQuery(query, Competence.class);
      @SuppressWarnings("unchecked")
      List<Competence> result=hibQuery.setMaxResults(3).list();
      return result;
   }

sanne.grinovero · **Posted:** Fri Oct 19, 2012 6:28 pm

since it's just 3 instances the easy option is that you iterate on them and pick what you want ;-)

If you had a lot or needed top efficiency you would need a custom Filter:
http://docs.jboss.org/hibernate/search/4.2/reference/en-US/html_single/#query-filter

jeremycod · **Joined:** Mon Jul 16, 2012 1:11 pm **Posts:** 12

sanne.grinovero wrote:

since it's just 3 instances the easy option is that you iterate on them and pick what you want ;-)

This doesn't work for me, as I want 3 instances after the filtering is performed. If I limit the query to 3 instances and pick up instances that satisfies criteria, then I could get less then 3 instances at the end.

sanne.grinovero wrote:

If you had a lot or needed top efficiency you would need a custom Filter:
http://docs.jboss.org/hibernate/search/4.2/reference/en-US/html_single/#query-filter

I used BooleanQuery with combination of Occur.MUST_NOT and keyword based query. It gives desired result. Is this good approach?

Code:

searchString=searchString.toLowerCase();
      Session session = persistence.currentManager();
      FullTextSession fullTextSession=Search.getFullTextSession(session);
      QueryBuilder qBuilder=fullTextSession.getSearchFactory().buildQueryBuilder().forEntity(Competence.class).get();
      Query query=qBuilder.keyword().wildcard().onField("title").matching(searchString+"*").createQuery();
      BooleanQuery bQuery=new BooleanQuery();
      bQuery.add(query, BooleanClause.Occur.MUST);
      for(Competence exComp:existingCompetences){
         Term omittedTerm=new Term("id",String.valueOf(exComp.getId()));
         bQuery.add(new TermQuery(omittedTerm),BooleanClause.Occur.MUST_NOT);
      }
      org.hibernate.Query hibQuery=fullTextSession.createFullTextQuery(bQuery, Competence.class);      
      List<Competence> result=hibQuery.setMaxResults(limit).list();
      return result;

sanne.grinovero · **Posted:** Sat Oct 20, 2012 3:26 pm

that's correct yes. Sorry I didn't understand your original question.

As an alternative to adding those boolean queries you could look into Filters; you would get the same functionality but the code looks a bit cleaner and it is likely to perform better.

jeremycod · **Joined:** Mon Jul 16, 2012 1:11 pm **Posts:** 12

Thanks.

Can you tell me in addition why above example doesn't returns instances for searchString containing space? For example, I have a Competence whose title is "Software engineering". It is listed while I'm typing the first word "software". However, once I add space and/or other letters, there is no results.

Zoran

sanne.grinovero · **Posted:** Sat Oct 20, 2012 5:22 pm

Quote:

Can you tell me in addition why above example doesn't returns instances for searchString containing space? For example, I have a Competence whose title is "Software engineering". It is listed while I'm typing the first word "software". However, once I add space and/or other letters, there is no results.

Depends on the chosen Analyzer and your analysis options. My guess is that you configured your @Field options to index test in analysed form but you're building the query as specific keywords.

Easiest way to understand it us to use Luke to open your index and inspect it how the terms look like when stored in the index: you have to match them.

Note that you are creating a keyword() Query. You might find it easier to match with a phrase() Query..