- NAME
- DESCRIPTION
- METHODS
- SEE ALSO

# NAME

Xapian::Enquire - Make queries against a database

# DESCRIPTION

This class provides an interface to the information retrieval system for the purpose of searching.

# METHODS

new
set_query

  takes either a ready made Xapian::Query or a scalar containing a query, which in that case will be passed to Xapian::Query's constructor, together with any other passed arguments.

set_query_object <query>
get_query
matches <start> <size> [<check_at_least>]

  Takes the start element, and maximum number of elements (and optionally the minimum number of matches to check), and returns an array tied to Xapian::MSet::Tied.

get_matching_terms_begin

  Returns a Xapian::TermIterator, pointing to the start of the stream.

get_matching_terms_end

  Returns a Xapian::TermIterator, pointing to the end of the stream.

set_collapse_key <collapse_key>
set_docid_order <order>

  Set the direction in which documents are ordered by document id in the returned MSet.

  This order only has an effect on documents which would otherwise have equal rank. When ordering by relevance without a sort key, this means documents with equal weight. For a boolean match with no sort key, this means all documents. And if a sort key is used, this means documents with equal sort key (and also equal weight if ordering on relevance before or after the sort key).

  order can be ENQ_ASCENDING (the default, docids sort in ascending order), ENQ_DESCENDING (docds sort in descending order), or ENQ_DONT_CARE (docids sort in whatever order is most efficient for the backend.)

  Note: If you add documents in strict date order, then a boolean search - i.e. set_weighting_scheme(Xapian::BoolWeight()) - with set_docid_order(Xapian::Enquire::DESCENDING) is an efficient way to perform "sort by date, newest first", and with set_docid_order(Xapian::Enquire::ASCENDING) a very efficient way to perform "sort by date, oldest first".

set_cutoff <percent_cutoff> [<weight_cutoff>]
set_sort_by_relevance

  Set the sorting to be by relevance only. This is the default.

set_sort_by_value <sort_key> [<ascending>]

  Set the sorting to be by value only.

  sort_key - value number to reorder on. Sorting is with a string compare. If ascending is true (the default) higher is better; if ascending is false, lower is better.

  ascending - If true, document values which sort higher by string compare are better. If false, the sort order is reversed. (default true)

set_sort_by_value_then_relevance <sort_key> [<ascending>]

  Set the sorting to be by value, then by relevance for documents with the same value.

  sort_key - value number to reorder on. Sorting is with a string compare. If ascending is true (the default) higher is better; if ascending is false, lower is better.

  ascending - If true, document values which sort higher by string compare are better. If false, the sort order is reversed. (default true)

set_sort_by_relevance_then_value <sort_key> [<ascending>]

  Set the sorting to be by relevance then value.

  Note that with the default BM25 weighting scheme parameters, non-identical documents will rarely have the same weight, so this setting will give very similar results to set_sort_by_relevance(). It becomes more useful with particular BM25 parameter settings (e.g. BM25Weight(1,0,1,0,0)) or custom weighting schemes.

  sort_key - value number to reorder on. Sorting is with a string compare. If ascending is true (the default) higher is better; if ascending is false, lower is better.

  ascending - If true, document values which sort higher by string compare are better. If false, the sort order is reversed. (default true)

set_sort_by_key <sorter> [<ascending>]

  Set the sorting to be by key only.

  sorter - the functor to use to build the key.

  ascending - If true, keys which sort higher by string compare are better. If false, the sort order is reversed. (default true)

set_sort_by_key_then_relevance <sorter> [<ascending>]

  Set the sorting to be by key, then by relevance for documents with the same key.

  sorter - the functor to use to build the key.

  ascending - If true, keys which sort higher by string compare are better. If false, the sort order is reversed. (default true)

set_sort_by_relevance_then_key <sorter> [<ascending>]

  Set the sorting to be by relevance then key.

  sorter - the functor to use to build the key.

  ascending - If true, keys which sort higher by string compare are better. If false, the sort order is reversed. (default true)

get_mset

  Get match set.

get_eset

  Get set of query expansion terms.

get_description

  Return a description of this object.

# SEE ALSO

Xapian::Query, Xapian::Database