Class DrillDownQuery

A Lucene.Net.Search.Query for drill-down over facet categories. You should call Add(string, params string[]) for every group of categories you want to drill-down over.

NOTE: if you choose to create your own Lucene.Net.Search.Query by calling Term(string, string, params string[]), it is recommended to wrap it with Lucene.Net.Search.ConstantScoreQuery and set the boost to 0.0f, so that it does not affect the scores of the documents.

Collection initializer note: To create and populate a DrillDownQuery in a single statement, you can use the following example as a guide: 
var drillDownQuery = new DrillDownQuery(config)
{
    { "Publish Date", "2019" },
    { "Publish Date", "2020" },
    { "Publish Date", "2021" },
    { "timestamp", NumericRangeQuery.NewInt64Range("timestamp", range.Min, range.Max, range.MinInclusive, range.MaxInclusive) },
    { "filter", GetFilter() }
};

Note

This API is experimental and might change in incompatible ways in the next release.

Inheritance
object
Query
DrillDownQuery
Inherited Members
Query.Boost
Query.ToString()
Query.CreateWeight(IndexSearcher)
Namespace: Lucene.Net.Facet
Assembly: Lucene.Net.Facet.dll
Syntax
public sealed class DrillDownQuery : Query, IEnumerable<BooleanClause>, IEnumerable<KeyValuePair<string, int>>, IEnumerable

Constructors

DrillDownQuery(FacetsConfig)

Creates a new DrillDownQuery without a base query, to perform a pure browsing query (equivalent to using Lucene.Net.Search.MatchAllDocsQuery as base).

Declaration
public DrillDownQuery(FacetsConfig config)
Parameters
Type Name Description
FacetsConfig config

DrillDownQuery(FacetsConfig, Query)

Creates a new DrillDownQuery over the given base query. Can be null, in which case the result Lucene.Net.Search.Query from Rewrite(IndexReader) will be a pure browsing query, filtering on the added categories only.

Declaration
public DrillDownQuery(FacetsConfig config, Query baseQuery)
Parameters
Type Name Description
FacetsConfig config
Query baseQuery

Methods

Add(string, Filter)

Expert: add a custom drill-down Filter, e.g. when drilling down after range faceting.

Declaration
public void Add(string dim, Filter subFilter)
Parameters
Type Name Description
string dim
Filter subFilter

Add(string, Query)

Expert: add a custom drill-down subQuery. Use this when you have a separate way to drill-down on the dimension than the indexed facet ordinals.

Declaration
public void Add(string dim, Query subQuery)
Parameters
Type Name Description
string dim
Query subQuery

Add(string, params string[])

Adds one dimension of drill downs; if you pass the same dimension more than once it is OR'd with the previous cofnstraints on that dimension, and all dimensions are AND'd against each other and the base query.

Declaration
public void Add(string dim, params string[] path)
Parameters
Type Name Description
string dim
string[] path

Clone()

Returns a clone of this query.

Declaration
public override object Clone()
Returns
Type Description
object
Overrides
Lucene.Net.Search.Query.Clone()

Equals(object)

Determines whether the specified object is equal to the current object.

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
object obj

The object to compare with the current object.
Returns
Type Description
bool

true if the specified object is equal to the current object; otherwise, false.
Overrides

GetEnumerator()

Returns an iterator on the clauses in this query. It implements the IEnumerable{BooleanClause} interface to make it possible to do:

foreach (BooleanClause clause in drillDownQuery) {}
Declaration
public IEnumerator<BooleanClause> GetEnumerator()
Returns
Type Description
IEnumerator<BooleanClause>

GetHashCode()

Serves as the default hash function.

Declaration
public override int GetHashCode()
Returns
Type Description
int

A hash code for the current object.
Overrides
Lucene.Net.Search.Query.GetHashCode()

Rewrite(IndexReader)

Expert: called to re-write queries into primitive queries. For example, a Lucene.Net.Search.PrefixQuery will be rewritten into a Lucene.Net.Search.BooleanQuery that consists of Lucene.Net.Search.TermQuerys.

Declaration
public override Query Rewrite(IndexReader r)
Parameters
Type Name Description
IndexReader r
Returns
Type Description
Query
Overrides
Lucene.Net.Search.Query.Rewrite(Lucene.Net.Index.IndexReader)

Term(string, string, params string[])

Creates a drill-down term.

Declaration
public static Term Term(string field, string dim, params string[] path)
Parameters
Type Name Description
string field
string dim
string[] path
Returns
Type Description
Term

ToString(string)

Prints a query to a string, with field assumed to be the default field and omitted.

Declaration
public override string ToString(string field)
Parameters
Type Name Description
string field
Returns
Type Description
string
Overrides

Implements