In lucene.net can we search for a content without giving field name..and it will search in all fields that are indexed?

Question

In lucene.net can we search for a content without giving field name..and it will search in all fields that are indexed.

Answer 1

You cannot search for content without giving field name, however you can use MultiFieldQueryParser to search in all available fields.

E.g

Dim queryParser = New MultiFieldQueryParser(Version.LUCENE_29, _
    indexReader__1.GetFieldNames(IndexReader.FieldOption.ALL).ToArray(), analyzer)

here is complete an example.

'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

Answer 2

It will search all fields which are specified in the schema as searched by default.

Answer 3

Use MultiFieldQueryParser to parse your queries, and provide it with a array of the field names you want searched.

The query doesn't need any special syntax. If your query is "cat hat" it will search all the specified fields for either of these terms. If your default operator is AND, it will require that each term be found in at least one field.