【发布时间】：2011-09-30 09:28:13
【问题描述】：
我使用以下代码创建（并经常更新）用户索引（此处为演示目的略短了一点）：
Lucene.Net.Store.Directory directory = FSDirectory.Open(new System.IO.DirectoryInfo("TestLuceneIndex"));
StandardAnalyzer standardAnalyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_29);
IndexWriter indexWriter = new IndexWriter(directory, standardAnalyzer, IndexWriter.MaxFieldLength.UNLIMITED);
Document doc = new Document();
doc.Add(new Field("UID", uid, Field.Store.YES, Field.Index.NOT_ANALYZED, Field.TermVector.NO));
doc.Add(new Field("GENDER", gender, Field.Store.YES, Field.Index.NOT_ANALYZED, Field.TermVector.NO));
doc.Add(new Field("COUNTRY", countrycode, Field.Store.YES, Field.Index.NOT_ANALYZED, Field.TermVector.NO));
doc.Add(new Field("CITY", citycode, Field.Store.YES, Field.Index.NOT_ANALYZED, Field.TermVector.NO));
doc.Add(new Field("USERDATA", userdata, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
doc.Add(new Field("USERINFO", userinfo, Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
indexWriter.UpdateDocument(new Term("UID", uid), doc);
indexWriter.Optimize();
indexWriter.Commit();
indexWriter.Close();
存储在索引中的值如下：
UID - 用户 ID（字符串 GUID）
GENDER - 性别标识（字符串“0”（未识别）“1”（男性）或“2”（女性）
COUNTRY - 国家代码（字符串，如“US”、“FR”等）
CITY - 城市代码（字符串“A121”、“C432”等）
USERDATA - 一长串用户详细信息（类似于“John Doe j.doe@gmail.com 设计师高等教育 5 年经验”）
USERINFO - 关于用户的长字符串（类似于“我的名字是 John Doe。我出生...”）
然后我在索引中执行搜索。我会在两个字段（USERDATA 和 USERINFO）中进行搜索，并在必要时按 GENDER、COUNTRY 和 CITY 过滤结果。结果我检索了 UID（我需要这个值来识别数据库中用户记录的 id）。
这是我用于搜索的代码：
Lucene.Net.Store.Directory directory = Lucene.Net.Store.FSDirectory.Open(new System.IO.DirectoryInfo("TestLuceneIndex");
standardAnalyzer = new Lucene.Net.Analysis.Standard.StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_29);
Lucene.Net.Index.IndexReader indexReader = Lucene.Net.Index.IndexReader.Open(directory, true);
indexSearcher = new Lucene.Net.Search.IndexSearcher(indexReader);
Lucene.Net.Search.BooleanQuery booleanQuery = new Lucene.Net.Search.BooleanQuery();
Lucene.Net.QueryParsers.MultiFieldQueryParser queryTextParser = new Lucene.Net.QueryParsers.MultiFieldQueryParser(Lucene.Net.Util.Version.LUCENE_29, new string[] { "USERDATA", "USERINFO" }, standardAnalyzer);
Lucene.Net.Search.Query queryText = queryTextParser.Parse(SearchText);
booleanQuery.Add(queryText, Lucene.Net.Search.BooleanClause.Occur.MUST);
if (searchGender != "0")
{
Lucene.Net.Index.Term termGender = new Lucene.Net.Index.Term("GENDER", searchGender);
Lucene.Net.Search.Query queryGender = new Lucene.Net.Search.TermQuery(termGender);
booleanQuery.Add(queryGender, Lucene.Net.Search.BooleanClause.Occur.MUST);
}
if (searchCity != "0")
{
Lucene.Net.Index.Term termCity = new Lucene.Net.Index.Term("CITY", searchCity);
Lucene.Net.Search.Query queryCity = new Lucene.Net.Search.TermQuery(termCity);
booleanQuery.Add(queryCity, Lucene.Net.Search.BooleanClause.Occur.MUST);
}
if (searchCountry != "0")
{
Lucene.Net.Index.Term termCountry = new Lucene.Net.Index.Term("COUNTRY", searchCountry);
Lucene.Net.Search.Query queryCountry = new Lucene.Net.Search.TermQuery(termCountry);
booleanQuery.Add(queryCountry, Lucene.Net.Search.BooleanClause.Occur.MUST);
}
Lucene.Net.Search.TopScoreDocCollector collector = Lucene.Net.Search.TopScoreDocCollector.create(indexReader.MaxDoc(), true);
indexSearcher.Search(booleanQuery, collector);
Lucene.Net.Search.ScoreDoc[] scoreDocs=collector.TopDocs().scoreDocs;
Lucene.Net.Highlight.Formatter formatter = new Lucene.Net.Highlight.SimpleHTMLFormatter("<b>", "</b>");
Lucene.Net.Highlight.QueryScorer queryScorer = new Lucene.Net.Highlight.QueryScorer(booleanQuery);
highlighter = new Lucene.Net.Highlight.Highlighter(formatter, queryScorer);
Lucene.Net.Highlight.Fragmenter fragmenter = new Lucene.Net.Highlight.SimpleFragmenter(150);
highlighter.SetTextFragmenter(fragmenter);
除了使用几个词时的相关性之外，一切都很好： 例如，当我搜索（microsoft .net 程序员）时，包含确切子字符串的结果的得分并不高于在不同文本位置包含这些单词的结果。我理解，这是由简单的事实引起的，即分数计算是基于文本中搜索字符串的百分比因子，而不是字符串重合的准确性。但是如何强制评分算法使资产准确性更有价值呢？ IE。如何强制在相关性计算中被认为更重要的词之间的距离？
【问题讨论】：
标签： lucene.net relevance