2010-12-21 105 views
6

我有问题,在.NET中排序我的lucene.net索引。我尝试了几乎每个解决方案在stackoverflow和寻找谷歌的答案。我正在使用Lucene.NET 2.9.2和ASP.NET 2.0。我想对字符串进行排序,就像在sql中一样,你可以键入'order by title desc [asc]'Lucene.net 2.9.2排序(排序不起作用)

我会告诉你我的代码,我希望有人能帮助我。

//Here I create Index with some fields 
    doc.Add(new Field("prod_id",row["prod_id"].ToString(),Field.Store.YES,Field.Index.ANALYZED)); 
      doc.Add(new Field("prod_title", row["prod_title"].ToString(), Field.Store.YES, Field.Index.ANALYZED)); 
      doc.Add(new Field("prod_desc", row["prod_desc"].ToString(), Field.Store.YES, Field.Index.ANALYZED)); 
      doc.Add(new Field("prod_author", row["prod_author"].ToString(), Field.Store.YES, Field.Index.ANALYZED)); 
      doc.Add(new Field("prod_publisher", row["prod_publisher"].ToString(), Field.Store.YES, Field.Index.ANALYZED)); 
      doc.Add(new Field("prod_price", row["prod_price"].ToString(), Field.Store.YES, Field.Index.ANALYZED)); 

//Then next I try to do search with sort option: 

//method for return approciate Sort object 
private static Sort SetSortForLucene(string _sort) 
    { 
     Sort sort; 
     switch (_sort) 
     { 
      case "UnitPriceGorss": 
       sort = new Sort(new SortField("prod_price",SortField.DOUBLE,false); 
       break; 

      case "UnitPriceGorssDESC": 
       sort = new Sort(new SortField("prod_price",SortField.DOUBLE,true); 
       break; 

      case "Title": 
       //not working 
       sort = new Sort(new SortField("prod_title", SortField.STRING, true)); 
       break; 

      case "TitleDESC": 
       //not working 
       sort = new Sort(new SortField("prod_title", SortField.STRING, false)); 
       break; 
      case "": 
       sort = new Sort(new SortField("prod_title", SortField.STRING, false)); 
       break; 
      default: 
       sort = new Sort(new SortField("prod_title", SortField.STRING, false)); 
       break; 
     } 
     return sort; 
    } 
//Inside my query of lucene method: 
StandardAnalyzer analizer = new StandardAnalyzer(Version.LUCENE_29); 
IndexReader reader =IndexReader.Open(IndexPath); 
Searcher searcher = new IndexSearcher(reader); 
//Here call for Sort object 
Sort sort = SetSortForLucene(_sort); 
TopFieldDocCollector collector = new TopFieldDocCollector(reader, sort, pageSize); 
//Find which document field need to me asked in QueryParser object 
string _luceneField = ""; 

     if (luceneField.Contains("_")) 
      _luceneField = luceneField; 
     else 
     switch (luceneField) 
     { 
      case "Title": _luceneField = "prod_title"; break; 
      case "Description": _luceneField = "prod_desc"; break; 
      case "Author": _luceneField = "prod_author"; break; 
      case "Publisher": _luceneField = "prod_publisher"; break; 
      default: _luceneField = "prod_title"; break; 
     } 
     QueryParser parser = new QueryParser(_luceneField, analizer); 
     Query query = parser.Parse(luceneQuery); 
     ScoreDoc[] hits; 
     searcher.Search(query,collector); 
//Obtaining top records from search but without any sort. 
     hits = collector.TopDocs().scoreDocs; 

     foreach (ScoreDoc hit in hits) 
     { 
      Document doc = searcher.Doc(hit.doc); 
      string a = doc.Get("prod_id"); 
      int id = 0; 
      if (hit.score > score) 
      { 
       if (int.TryParse(doc.Get("prod_id"), out id)) 
           tmpId.Add(id); 
      } 
     } 
//I also define stop words for full text searching and i think this is 
//real cause of problem with sorting. 
System.String[] stopWords = new System.String[]{"a","że","w","przy","o","bo","co","z","za","ze","ta","i","no","do"}; 

我用这个link in stackoverflow.this pretty one link解决我的问题,但排序失败,我不知道什么是错我的代码。

几天后终于找到了解决办法。当我想排序的字段表示字符串值时,它不会被标记。

例如,当我想标题(升/降),以产品分类,你应该把这样的事情:

doc.Add(new Field(Product.PROD_TITLE_SORT, row["prod_title"].ToString().Replace(" ", "_") + "_" + row[Product.PROD_ID].ToString(), Field.Store.NO, Field.Index.NOT_ANALYZED)); 

我不明白的是为什么实际上这个领域并不存储和不analizyng因此lucene.net可以通过这个添加的字段进行排序。这种排序领域甚至不在索引!我使用lukeall-1.0.1.jar索引浏览器进行了检查。

其次,你需要创建一个适当的排序方法:

private static Sort SetSortForLucene(string _sort) 
     { 
      Sort sort; 
      _sort = !string.IsNullOrEmpty(_sort) ? _sort : ""; 
      switch (_sort) 
      { 
       case "UnitPriceGorss": 
        sort = new Sort(new SortField(PROD_PRICE, SortField.DOUBLE, false)); 
        break; 

       case "UnitPriceGorssDESC": 
        sort = new Sort(new SortField(PROD_PRICE, SortField.DOUBLE, true)); 
        break; 

       case "Title": 
        //not it works perfectly. 
        sort = new Sort(new SortField(PROD_TITLE_SORT, SortField.STRING, true)); 
        break; 

       case "TitleDESC": 
        //not it works perfectly. 
        sort = new Sort(new SortField(PROD_TITLE_SORT, SortField.STRING, false)); 
        break; 
       case ""://Here is default sorting behavior. It get's result according to Lucene.NET search result score. 
        sort = new Sort(SortField.FIELD_SCORE); 
        break; 
       default: 
        sort = new Sort(SortField.FIELD_SCORE); 
        break; 
      } 
      return sort; 
     } 

是什么让我真的怀疑是那种可与SortField.DOUBLE场时,在Lucene的全文索引被索引。

我希望这篇文章能够帮助任何有类似排序问题的人。

回答

6

该字段不需要存储,除非您要在查询中返回数据。但是它仍然被添加到索引中。

你不分析你想分类的字段的原因是分析器将字段分成单独的条件,这使得排序非常困难,因为文档的索引会有多个单词,显然不能按照整个指数排序。这适用于所有字段类型,不管它们是否是单个字段。

我相信你可以存储字段,但除非你想在你的查询返回它,没有必要。

4

我怀疑有关排序的一件重要的事情。

它不适用于标记化(分析)的数据。

+0

因此....为您希望排序的数据添加一个未分析字段,并将其用于排序,如果您还希望对其进行分析,则可能必须复制该字段。 – Myster 2014-07-17 03:41:38