A BooleanQuery is used for combining many queries into one. This is best illustrated with an example.
Lets say we wanted to find all documents with the term “Ruby” in the :title and the term “Ferret” in the :content field or the :title field written before January 2006. You could build the query like this.
tq1 = TermQuery.new(:title, "ruby") tq21 = TermQuery.new(:title, "ferret") tq22 = TermQuery.new(:content, "ferret") bq2 = BooleanQuery.new bq2 << tq21 << tq22 rq3 = RangeQuery.new(:written, :< => "200601") query = BooleanQuery.new query.add_query(tq1, :must).add_query(bq2, :must).add_query(rq3, :must)
Create a new BooleanQuery. If you don’t care about the scores of the sub-queries added to the query (as would be the case for many automatically generated queries) you can disable the coord_factor of the score. This will slightly improve performance for the query. Usually you should leave this parameter as is.
static VALUE frb_bq_init(int argc, VALUE *argv, VALUE self) { VALUE rcoord_disabled; bool coord_disabled = false; Query *q; if (rb_scan_args(argc, argv, "01", &rcoord_disabled)) { coord_disabled = RTEST(rcoord_disabled); } q = bq_new(coord_disabled); Frt_Wrap_Struct(self, &frb_bq_mark, &frb_q_free, q); object_add(q, self); return self; }
Us this method to add sub-queries to a BooleanQuery. You can either add a straight Query or a BooleanClause. When adding a Query, the default occurrence requirement is :should. That is the Query’s match will be scored but it isn’t essential for a match. If the query should be essential, use :must. For exclusive queries use :must_not.
When adding a Boolean clause to a BooleanQuery there is no need to set the occurrence property because it is already set in the BooleanClause. Therefor the occur parameter will be ignored in this case.
query | Query to add to the BooleanQuery |
occur | occurrence requirement for the query being added. Must be one of
|
returns | BooleanClause which was added |
static VALUE frb_bq_add_query(int argc, VALUE *argv, VALUE self) { GET_Q(); VALUE rquery, roccur; BCType occur = BC_SHOULD; Query *sub_q; VALUE klass; if (rb_scan_args(argc, argv, "11", &rquery, &roccur) == 2) { occur = frb_get_occur(roccur); } klass = CLASS_OF(rquery); if (klass == cBooleanClause) { BooleanClause *bc = (BooleanClause *)DATA_PTR(rquery); if (argc > 1) { rb_warning("Second argument to BooleanQuery#add is ignored " "when adding BooleanClause"); } bq_add_clause(q, bc); return rquery; } else if (TYPE(rquery) == T_DATA) { Data_Get_Struct(rquery, Query, sub_q); return frb_bc_wrap(bq_add_query(q, sub_q, occur)); } else { rb_raise(rb_eArgError, "Cannot add %s to a BooleanQuery", rb_class2name(klass)); } return self; }
Us this method to add sub-queries to a BooleanQuery. You can either add a straight Query or a BooleanClause. When adding a Query, the default occurrence requirement is :should. That is the Query’s match will be scored but it isn’t essential for a match. If the query should be essential, use :must. For exclusive queries use :must_not.
When adding a Boolean clause to a BooleanQuery there is no need to set the occurrence property because it is already set in the BooleanClause. Therefor the occur parameter will be ignored in this case.
query | Query to add to the BooleanQuery |
occur | occurrence requirement for the query being added. Must be one of
|
returns | BooleanClause which was added |
static VALUE frb_bq_add_query(int argc, VALUE *argv, VALUE self) { GET_Q(); VALUE rquery, roccur; BCType occur = BC_SHOULD; Query *sub_q; VALUE klass; if (rb_scan_args(argc, argv, "11", &rquery, &roccur) == 2) { occur = frb_get_occur(roccur); } klass = CLASS_OF(rquery); if (klass == cBooleanClause) { BooleanClause *bc = (BooleanClause *)DATA_PTR(rquery); if (argc > 1) { rb_warning("Second argument to BooleanQuery#add is ignored " "when adding BooleanClause"); } bq_add_clause(q, bc); return rquery; } else if (TYPE(rquery) == T_DATA) { Data_Get_Struct(rquery, Query, sub_q); return frb_bc_wrap(bq_add_query(q, sub_q, occur)); } else { rb_raise(rb_eArgError, "Cannot add %s to a BooleanQuery", rb_class2name(klass)); } return self; }
Disabled; run with --debug to generate this.
Generated with the Darkfish Rdoc Generator 1.1.6.