Package org.apache.lucene.facet

# Class DrillDownQuery

java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.facet.DrillDownQuery

public final class DrillDownQuery extends Query
A `Query` for drill-down over facet categories. You should call `add(String, String...)` for every group of categories you want to drill-down over.

NOTE: if you choose to create your own `Query` by calling `term(java.lang.String, java.lang.String, java.lang.String...)`, it is recommended to wrap it in a `BoostQuery` with a boost of `0.0f`, so that it does not affect the scores of the documents.

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

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DrillDownQuery(FacetsConfig config)`
  Creates a new `DrillDownQuery` without a base query, to perform a pure browsing query (equivalent to using `MatchAllDocsQuery` as base).
  `DrillDownQuery(FacetsConfig config, Query baseQuery)`
  Creates a new `DrillDownQuery` over the given base query.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `add(String dim, String... path)`
  Adds one dimension of drill downs; if you pass the same dimension more than once it is OR'd with the previous constraints on that dimension, and all dimensions are AND'd against each other and the base query.
  `void`
  `add(String dim, Query subQuery)`
  Expert: add a custom drill-down subQuery.
  `DrillDownQuery`
  `clone()`
  `boolean`
  `equals(Object other)`
  `Query`
  `getBaseQuery()`
  Returns the internal baseQuery of the DrillDownQuery
  `Query[]`
  `getDrillDownQueries()`
  Returns the dimension queries added either via `add(String, Query)` or `add(String, String...)`
  `int`
  `hashCode()`
  `Query`
  `rewrite(IndexSearcher indexSearcher)`
  `static Term`
  `term(String field, String dim, String... path)`
  Creates a drill-down term.
  `String`
  `toString(String field)`
  `void`
  `visit(QueryVisitor visitor)`

  ### Methods inherited from class org.apache.lucene.search.Query

  `classHash, createWeight, sameClassAs, toString`

  ### Methods inherited from class java.lang.Object

  `finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### DrillDownQuery

    public DrillDownQuery(FacetsConfig config)
    Creates a new `DrillDownQuery` without a base query, to perform a pure browsing query (equivalent to using `MatchAllDocsQuery` as base).

  - ### DrillDownQuery

    public DrillDownQuery(FacetsConfig config, Query baseQuery)
    Creates a new `DrillDownQuery` over the given base query. Can be `null`, in which case the result `Query` from `Query.rewrite(IndexSearcher)` will be a pure browsing query, filtering on the added categories only.

- ## Method Details

  - ### term

    public static Term term(String field, String dim, String... path)
    Creates a drill-down term.

  - ### add

    public void add(String dim, String... path)
    Adds one dimension of drill downs; if you pass the same dimension more than once it is OR'd with the previous constraints on that dimension, and all dimensions are AND'd against each other and the base query.

  - ### add

    public void add(String dim, Query subQuery)
    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.

  - ### clone

    public DrillDownQuery clone()
    Overrides:
      `clone` in class `Object`

  - ### hashCode

    public int hashCode()
    Specified by:
      `hashCode` in class `Query`

  - ### equals

    public boolean equals(Object other)
    Specified by:
      `equals` in class `Query`

  - ### rewrite

    public Query rewrite(IndexSearcher indexSearcher) throws IOException
    Overrides:
      `rewrite` in class `Query`
    Throws:
      `IOException`

  - ### toString

    public String toString(String field)
    Specified by:
      `toString` in class `Query`

  - ### visit

    public void visit(QueryVisitor visitor)
    Specified by:
      `visit` in class `Query`

  - ### getBaseQuery

    public Query getBaseQuery()
    Returns the internal baseQuery of the DrillDownQuery
    Returns:
      The baseQuery used on initialization of DrillDownQuery

  - ### getDrillDownQueries

    public Query[] getDrillDownQueries()
    Returns the dimension queries added either via `add(String, Query)` or `add(String, String...)`
    Returns:
      The array of dimQueries