Multifield search in Lucene

Question

Hi,

I need to do a multi-field level search on Books database using Lucene.

for example:my search criteria is something like:

(Author:a1 and title:t1)  OR (Author:a2 and title:t2) OR (Author:a3 and title:t3)

where a1, t1 etc are author names and book titles respectively. How do I get my Lucene Query object built for this kind of criteria?

Thanks!

Answer 1

The following code assumes a1, a2, a3, t1, t2, t3 are terms. If they are phrases, you will need to use PhraseQuery instead of TermQuery.

    // Create a BooleanQuery for (Author:a1 and title:t1)

BooleanQuery a1AndT1 = new BooleanQuery();
a1AndT1.add(new TermQuery(new Term("Author", "a1")), BooleanClause.Occur.MUST);
a1AndT1.add(new TermQuery(new Term("title", "t1")), BooleanClause.Occur.MUST);

// Create a BooleanQuery for (Author:a2 and title:t2)

BooleanQuery a2AndT2 = new BooleanQuery();
a2AndT2.add(new TermQuery(new Term("Author", "a2")), BooleanClause.Occur.MUST);
a2AndT2.add(new TermQuery(new Term("title", "t2")), BooleanClause.Occur.MUST);

// Create a BooleanQuery for (Author:a3 and title:t3)

BooleanQuery a3AndT3 = new BooleanQuery();
a3AndT3.add(new TermQuery(new Term("Author", "a3")), BooleanClause.Occur.MUST);
a3AndT3.add(new TermQuery(new Term("title", "t3")), BooleanClause.Occur.MUST);

// Create a BooleanQuery that combines the OR-clauses

BooleanQuery query = new BooleanQuery();
query.add(a1AndT1, BooleanClause.Occur.SHOULD);
query.add(a2AndT2, BooleanClause.Occur.SHOULD);
query.add(a3AndT3, BooleanClause.Occur.SHOULD);

// As you can see, the resulting Lucene query is 
// (+Author:a1 +title:t1) (+Author:a2 +title:t2) (+Author:a3 +title:t3)
// which behaves the same as something like
// (Author:a1 and title:t1) OR (Author:a2 and title:t2) OR (Author:a3 and title:t3)

System.out.println(query);