Lucene搜索语法

时间:2014-08-23 18:54:48

标签: c# search lucene.net

我需要帮助确定在给定情况下使用哪些查询类型。

我认为我说得对,如果我在lucene字段中存储“FORD”这个词,我想找到完全匹配,我会使用TermQuery吗?

但是我应该使用哪种查询类型,如果我在寻找单词“FORD”,其中字段的内容存储为: -

  

“FORD | HONDA | SUZUKI”

如果我要搜索整个页面的内容,寻找短语怎么办?比如“请帮助我”?

2 个答案:

答案 0 :(得分:3)

如果您想在FORD|HONDA|SUZUKI中搜索FORD,请使用 Field.Index.ANALYZED 进行索引,或将其存储如下以使用 TermQuery

var analyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30);
var fs = FSDirectory.Open("test.index");

//Index a Test Document
IndexWriter wr = new IndexWriter(fs, analyzer, true, IndexWriter.MaxFieldLength.LIMITED);
var doc = new Document();

doc.Add(new Field("Model", "FORD", Field.Store.YES, Field.Index.NOT_ANALYZED));
doc.Add(new Field("Model", "HONDA", Field.Store.YES, Field.Index.NOT_ANALYZED));
doc.Add(new Field("Model", "SUZUKI", Field.Store.YES, Field.Index.NOT_ANALYZED));

doc.Add(new Field("Text", @"What if i was to search the contents of an entire page, looking for a phrase? such as ""please help me""?", 
                    Field.Store.YES, Field.Index.ANALYZED));

wr.AddDocument(doc);
wr.Commit();

var reader = wr.GetReader();
var searcher = new IndexSearcher(reader);

//Use TermQuery for "NOT_ANALYZED" fields
var result = searcher.Search(new TermQuery(new Term("Model", "FORD")), 100);
foreach (var item in result.ScoreDocs)
{
    Console.WriteLine("1)" + reader.Document(item.Doc).GetField("Text").StringValue);
}

//Use QueryParser for "ANALYZED" fields
var qp = new QueryParser(Lucene.Net.Util.Version.LUCENE_30, "Text", analyzer);
result = searcher.Search(qp.Parse(@"""HELP ME"""), 100);
foreach (var item in result.ScoreDocs)
{
    Console.WriteLine("2)" + reader.Document(item.Doc).GetField("Text").StringValue);
}

TermQuery 意味着您要搜索术语,因为它存储在索引中,这取决于您为该字段编制索引的方式(NOT_ANALYZED,ANALYZED + WhichAnalyzer)。最常见的用途是使用 NOT_ANALYZED 字段。

你也可以将 TermQuery ANALYZED 字段一起使用,但是你应该知道 analyzer 如何标记你的输入字符串。下面是一个示例,了解分析器如何标记您的输入

var text = @"What if i was to search the contents of an entire page, looking for a phrase? such as ""please help me""?";
var analyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30 );
//var analyzer = new WhitespaceAnalyzer();
//var analyzer = new KeywordAnalyzer();
//var analyzer = new SimpleAnalyzer();

var ts = analyzer.TokenStream("", new StringReader(text));
var termAttr = ts.GetAttribute<ITermAttribute>();

while (ts.IncrementToken())
{
    Console.Write("[" + termAttr.Term + "] " );    
}

答案 1 :(得分:1)

我会把问题横向转向,所以我将每个字段的多个值分别放在索引中 - 这应该使搜索更简单。查看Field Having Multiple Values可能会有所帮助。