Lucene.NET search index approach
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++)
开发者_运维知识库{
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
A few ideas to think about:
- Try the search "Tags:Something" (you had lowercased the field name "Tags" on your example)
- I think you'll need a per-field analyser: one for "Id" and one for "Tags
- Luke is a really good tool for examining indices and queries (it works fine for Lucene.net created data)
Hope this helps,
It appears you can add multiple fields with the same name to a document so I changed my code to:
foreach (string tag in vehicle.Tags)
{
var tags = new Field(
TAGS,
tag,
Field.Store.YES,
Field.Index.ANALYZED,
Field.TermVector.YES);
doc.Add(tags);
}
I can now search by single or multiple tags in the "Tags" field.
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