Merge branch 'pr/feature/optimize-sparql-query-build-unions' into dev…

…elopment

lib/goo/sparql/query_builder.rb

@@ -30,7 +30,7 @@ def build_select_query(ids, variables, graphs, patterns,
           variables, optional_patterns = get_aggregate_vars(@aggregate, @collection, graphs,
                                                             @klass, @unions, variables, internal_variables)
 
-        @order_by, variables, patterns = init_order_by(@count, @klass, @order_by, patterns, variables)
+        @order_by, variables, @unions = init_order_by(@count, @klass, @order_by, @unions, variables)
         variables, patterns = add_some_type_to_id(patterns, query_options, variables)
 
         query_filter_str, patterns, optional_patterns =
@@ -258,19 +258,20 @@ def get_client
         Goo.sparql_query_client(@store)
       end
 
-      def init_order_by(count, klass, order_by, patterns, variables)
+      def init_order_by(count, klass, order_by, unions, variables)
         order_by = nil if count
         if order_by
           order_by = order_by.first
           #simple ordering ... needs to use pattern inspection
           order_by.each do |attr, direction|
             quad = query_pattern(klass, attr)
-            patterns << quad[1]
+            unions << [quad[1]]
+            #patterns << quad[1]
             #mdorf, 9/22/16 If an ORDER BY clause exists, the columns used in the ORDER BY should be present in the SPARQL select
             variables << attr unless variables.include?(attr)
           end
         end
-        [order_by, variables, patterns]
+        [order_by, variables, unions]
       end
 
       def sparql_op_string(op)