Support for COUNT(DISTINCT ?foo)

ruby-rdf · Nov 14, 2012 · 2d35125 · 2d35125
1 parent 6e45949
commit 2d35125
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/lib/sparql/client/query.rb b/lib/sparql/client/query.rb
@@ -300,12 +300,13 @@ def to_s
       buffer = [form.to_s.upcase]
       case form
         when :select, :describe
-          buffer << 'DISTINCT' if options[:distinct]
+          only_count = values.empty? and options[:count]
+          buffer << 'DISTINCT' if options[:distinct] and not only_count
           buffer << 'REDUCED'  if options[:reduced]
           buffer << ((values.empty? and not options[:count]) ? '*' : values.map { |v| serialize_value(v[1]) }.join(' '))
           if options[:count]
             options[:count].each do |var, count|
-              buffer << '( COUNT(' + (var.is_a?(String) ? var : "?#{var}") + ') AS ' + (count.is_a?(String) ? count : "?#{count}") + ' )'
+              buffer << '( COUNT(' + (options[:distinct] ? 'DISTINCT ' : '') + (var.is_a?(String) ? var : "?#{var}") + ') AS ' + (count.is_a?(String) ? count : "?#{count}") + ' )'
             end
           end
         when :construct

diff --git a/spec/query_spec.rb b/spec/query_spec.rb
@@ -59,6 +59,7 @@
 
     it "should support COUNT" do
       @query.select(:count => { :s => :c }).where([:s, :p, :o]).to_s.should == "SELECT  ( COUNT(?s) AS ?c ) WHERE { ?s ?p ?o . }"
+      @query.select(:count => { :s => :c }, :distinct => true).where([:s, :p, :o]).to_s.should == "SELECT  ( COUNT(DISTINCT ?s) AS ?c ) WHERE { ?s ?p ?o . }"
       @query.select(:count => { :s => '?c' }).where([:s, :p, :o]).to_s.should == "SELECT  ( COUNT(?s) AS ?c ) WHERE { ?s ?p ?o . }"
       @query.select(:count => { '?s' => '?c' }).where([:s, :p, :o]).to_s.should == "SELECT  ( COUNT(?s) AS ?c ) WHERE { ?s ?p ?o . }"
       @query.select(:o, :count => { :s => :c }).where([:s, :p, :o]).to_s.should == "SELECT ?o ( COUNT(?s) AS ?c ) WHERE { ?s ?p ?o . }"