vb.net 如何在 QueryParser 中合并多个字段？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/468405/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to incorporate multiple fields in QueryParser?
提问by user57175
Dim qp1 As New QueryParser("filename", New StandardAnalyzer())
Dim qp2 As New QueryParser("filetext", New StandardAnalyzer())
.
.
I am using the 'Lucene.Net' library and have the following question.
我正在使用“Lucene.Net”库并有以下问题。
Instead of creating two separate QueryParserobjects and using them to obtain two Hits objects, is it possible perform a search on both fields using a single QueryParserobject, so that I have only one Hits object which gives me the overall score of each Document?
QueryParser是否可以使用单个QueryParser对象在两个字段上执行搜索，而不是创建两个单独的对象并使用它们来获取两个 Hits对象，以便我只有一个 Hits 对象，它可以为我提供每个文档的总分？
回答by Sam Doshi
There are 3 ways to do this.
有 3 种方法可以做到这一点。
The first way is to construct a query manually, this is what QueryParseris doing internally. This is the most powerful way to do it, and means that you don't have to parse the user input if you want to prevent access to some of the more exotic features of QueryParser:
第一种方法是手动构造查询，这是QueryParser内部所做的。这是执行此操作的最强大方法，这意味着如果您想阻止访问以下一些更奇特的功能，则不必解析用户输入QueryParser：
IndexReader reader = IndexReader.Open("<lucene dir>");
Searcher searcher = new IndexSearcher(reader);
BooleanQuery booleanQuery = new BooleanQuery();
Query query1 = new TermQuery(new Term("filename", "<text>"));
Query query2 = new TermQuery(new Term("filetext", "<text>"));
booleanQuery.add(query1, BooleanClause.Occur.SHOULD);
booleanQuery.add(query2, BooleanClause.Occur.SHOULD);
// Use BooleanClause.Occur.MUST instead of BooleanClause.Occur.SHOULD
// for AND queries
Hits hits = searcher.Search(booleanQuery);
The second way is to use MultiFieldQueryParser, this behaves like QueryParser, allowing access to all the power that it has, except that it will search over multiple fields.
第二种方法是使用MultiFieldQueryParser，它的行为类似于QueryParser，允许访问它所拥有的所有功能，除了它将搜索多个字段。
IndexReader reader = IndexReader.Open("<lucene dir>");
Searcher searcher = new IndexSearcher(reader);
Analyzer analyzer = new StandardAnalyzer();
MultiFieldQueryParser queryParser = new MultiFieldQueryParser(
new string[] {"filename", "filetext"},
analyzer);
Hits hits = searcher.Search(queryParser.parse("<text>"));
The final way is to use the special syntax of QueryParsersee here.
最后一种方法是使用QueryParsersee here的特殊语法。
IndexReader reader = IndexReader.Open("<lucene dir>");
Searcher searcher = new IndexSearcher(reader);
Analyzer analyzer = new StandardAnalyzer();
QueryParser queryParser = new QueryParser("<default field>", analyzer);
// <default field> is the field that QueryParser will search if you don't
// prefix it with a field.
string special = "filename:" + text + " OR filetext:" + text;
Hits hits = searcher.Search(queryParser.parse(special));
Your other option is to create new field when you index your content called filenameandtext, into which you can place the contents of bothfilename and filetext, then you only have to search one field.
您的另一种选择是创建新的领域时filenameandtext叫你索引你的内容，可以在其中放置的内容既文件名和FILETEXT，那么你只需要搜索一个领域。
回答by Bob King
Just build a query string with each term:
只需为每个术语构建一个查询字符串：
"filename:searchText OR filetext:searchText"
It doesn't matter what you pass as the initial field in QueryParser's constructor. Just make sure you call .Parse() on your query string to get a Query object back to execute.
在 QueryParser 的构造函数中作为初始字段传递什么并不重要。只需确保在查询字符串上调用 .Parse() 以获取 Query 对象以执行。
If you want to use an "and" search:
如果要使用“和”搜索：
"+filename:searchText +filetext:searchText"
回答by vijay shiyani
** you can also use MultiFieldQueryParserto search in all available fields.**
** 您还可以使用MultiFieldQueryParser在所有可用字段中进行搜索。**
E.g
例如
Dim queryParser = New MultiFieldQueryParser(Version.LUCENE_29,
indexReader__1.GetFieldNames(IndexReader.FieldOption.ALL).ToArray(), analyzer)
here is complete an example.
这是一个完整的例子。
//get index directory
Dim directory As Directory = FSDirectory.Open(New DirectoryInfo(HostingEnvironment.MapPath(VirtualIndexPath)))
//get analyzer
Dim analyzer As Analyzer = New StandardAnalyzer(Version.LUCENE_29)
//get index reader and searcher
Dim indexReader__1 As IndexReader = IndexReader.Open(directory, True)
Dim indexSearch As Searcher = New IndexSearcher(indexReader__1)
//add all possible fileds in multifieldqueryparser using indexreader getFieldNames method
Dim queryParser = New MultiFieldQueryParser(Version.LUCENE_29, indexReader__1.GetFieldNames(IndexReader.FieldOption.ALL).ToArray(), analyzer)
Dim query = queryParser.Parse(Criteria)
Dim resultDocs As TopDocs = Nothing
//perform search
resultDocs = indexSearch.Search(query, indexReader__1.MaxDoc())
Dim hits = resultDocs.scoreDocs
hope that help
希望有所帮助
回答by Saltire
for each field create a query from the above queryparsers, then add the query to a booleanquery stating that it "must" occur.
对于每个字段，从上述查询解析器创建一个查询，然后将该查询添加到一个布尔查询中，说明它“必须”发生。
Alternatively, check out the MultiFieldQueryParser, which is a simplified way of doing it.
或者，查看 MultiFieldQueryParser，这是一种简化的方法。
