## org.apache.lucene.search.join
Class ToChildBlockJoinQuery

    java.lang.Object
      org.apache.lucene.search.Query
          org.apache.lucene.search.join.ToChildBlockJoinQuery

All Implemented Interfaces:
  Serializable, Cloneable

    public class ToChildBlockJoinQuery

extends org.apache.lucene.search.Query

Just like `ToParentBlockJoinQuery`, except this query joins in reverse: you provide a Query matching parent documents and it joins down to child documents.

WARNING: to create the parents filter, always use `RawTermFilter` (so that the filter includes deleted docs), wrapped with `CachingWrapperFilter` (so that the returned bit set per reader is a `FixedBitSet`), specifying DeletesMode.IGNORE (so that on reopen, the filter still includes deleted docs). Failure to do this can result in completely wrong documents being returned! For example:

       Filter parents = new CachingWrapperFilter(
                              new RawTermFilter(new Term("parent", "yes")),
                              CachingWrapperFilter.DeletesMode.IGNORE);

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

Constructor Summary
`ToChildBlockJoinQuery(org.apache.lucene.search.Query parentQuery, org.apache.lucene.search.Filter parentsFilter, boolean doScores)`

Method Summary
`Object` `clone()`
`org.apache.lucene.search.Weight` `createWeight(org.apache.lucene.search.Searcher searcher)`
`boolean` `equals(Object _other)`
`void` `extractTerms(Set<org.apache.lucene.index.Term> terms)`
`int` `hashCode()`
`org.apache.lucene.search.Query` `rewrite(org.apache.lucene.index.IndexReader reader)`
`String` `toString(String field)`

Methods inherited from class org.apache.lucene.search.Query
`combine, getBoost, getSimilarity, mergeBooleanQueries, setBoost, toString, weight`

Methods inherited from class java.lang.Object
`finalize, getClass, notify, notifyAll, wait, wait, wait`

Constructor Detail

### ToChildBlockJoinQuery

    public ToChildBlockJoinQuery(org.apache.lucene.search.Query parentQuery,
                                 org.apache.lucene.search.Filter parentsFilter,
                                 boolean doScores)

Method Detail

### createWeight

    public org.apache.lucene.search.Weight createWeight(org.apache.lucene.search.Searcher searcher)
                                                 throws IOException

  Overrides:
    `createWeight` in class `org.apache.lucene.search.Query`
  Throws:
    `IOException`

### extractTerms

    public void extractTerms(Set<org.apache.lucene.index.Term> terms)

  Overrides:
    `extractTerms` in class `org.apache.lucene.search.Query`

### rewrite

    public org.apache.lucene.search.Query rewrite(org.apache.lucene.index.IndexReader reader)
                                           throws IOException

  Overrides:
    `rewrite` in class `org.apache.lucene.search.Query`
  Throws:
    `IOException`

### toString

    public String toString(String field)

  Specified by:
    `toString` in class `org.apache.lucene.search.Query`

### equals

    public boolean equals(Object _other)

  Overrides:
    `equals` in class `org.apache.lucene.search.Query`

### hashCode

    public int hashCode()

  Overrides:
    `hashCode` in class `org.apache.lucene.search.Query`

### clone

    public Object clone()

  Overrides:
    `clone` in class `org.apache.lucene.search.Query`