Lucene.NET search index approach
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            by Tim Peel
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        Published on 2010-03-30T22:22:57Z
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            2010/03/31
            1:13 UTC
        
        
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Hi,
I am trying to put together a test case for using Lucene.NET on one of our websites. I'd like to do the following:
Index in a single unique id. Index across a comma delimitered string of terms or tags.
For example.
Item 1: Id = 1 Tags = Something,Separated-Term
I will then be structuring the search so I can look for documents against tag i.e.
tags:something OR tags:separate-term
I need to maintain the exact term value in order to search against it.
I have something running, and the search query is being parsed as expected, but I am not seeing any results. Here's some code.
My parser (_luceneAnalyzer is passed into my indexing service):
var parser = new QueryParser(Lucene.Net.Util.Version.LUCENE_CURRENT, "Tags", _luceneAnalyzer);
parser.SetDefaultOperator(QueryParser.Operator.AND);
return parser;
My Lucene.NET document creation:
var doc = new Document();
var id = new Field(
    "Id",
    NumericUtils.IntToPrefixCoded(indexObject.id),
    Field.Store.YES,
    Field.Index.NOT_ANALYZED,
    Field.TermVector.NO);
var tags = new Field(
    "Tags",
    string.Join(",", indexObject.Tags.ToArray()),
    Field.Store.NO,
    Field.Index.ANALYZED,
    Field.TermVector.YES);
doc.Add(id);
doc.Add(tags);
return doc;
My search:
var parser = BuildQueryParser();
var query = parser.Parse(searchQuery);
var searcher = Searcher;
TopDocs hits = searcher.Search(query, null, max);
IList<SearchResult> result = new List<SearchResult>();
float scoreNorm = 1.0f / hits.GetMaxScore();
for (int i = 0; i < hits.scoreDocs.Length; i++)
{
    float score = hits.scoreDocs[i].score * scoreNorm;
    result.Add(CreateSearchResult(searcher.Doc(hits.scoreDocs[i].doc), score));
}
return result;
I have two documents in my index, one with the tag "Something" and one with the tags "Something" and "Separated-Term". It's important for the - to remain in the terms as I want an exact match on the full value.
When I search with "tags:Something" I do not get any results.
Question
What Analyzer should I be using to achieve the search index I am after? Are there any pointers for putting together a search such as this? Why is my current search not returning any results?
Many thanks
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