ARQ - Sub Queries - SELECT

ARQ includes support for nested SELECTs.

Experimental feature.

This involves is syntactic extension and is available if the query is parsed with language Syntax.syntaxARQ.

Nested SELECT

A SELECT query can be placed inside a graph pattern to produce a table that is used within the outer query. A nested SELECT statement is enclosed in {} and is the only element in that group.

Example: find toys with more than five orders:

PREFIX : <http://example/>
SELECT ?x
{ 
  ?x a :Toy .
  { SELECT ?x ( count(?order) as ?q ) { ?x :order ?order } GROUP BY ?x }
  FILTER ( ?q > 5 )
}

 

ARQ Documentation Page