Do not use the cache for select('distinct ...')

orslumen · Sep 7, 2015 · 5e0e627 · 5e0e627
1 parent 52d06b4
commit 5e0e627
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Showing 4 changed files with 7 additions and 3 deletions.
diff --git a/lib/record_cache/datastore/active_record_30.rb b/lib/record_cache/datastore/active_record_30.rb
@@ -173,7 +173,7 @@ def visit_Arel_Nodes_SelectCore o
         @cacheable = false unless o.groups.empty?
         visit o.froms  if @cacheable
         visit o.wheres if @cacheable
-        # skip o.projections
+        @cacheable = o.projections.none?{ |projection| projection.to_s =~ /distinct/i } unless o.projections.empty?
       end
 
       def visit_Arel_Nodes_SelectStatement o

diff --git a/lib/record_cache/datastore/active_record_31.rb b/lib/record_cache/datastore/active_record_31.rb
@@ -199,7 +199,7 @@ def visit_Arel_Nodes_SelectCore o
         visit o.froms  if @cacheable
         visit o.wheres if @cacheable
         visit o.source if @cacheable
-        # skip o.projections
+        @cacheable = o.projections.none?{ |projection| projection.to_s =~ /distinct/i } unless o.projections.empty?
       end
 
       def visit_Arel_Nodes_SelectStatement o

diff --git a/lib/record_cache/datastore/active_record_32.rb b/lib/record_cache/datastore/active_record_32.rb
@@ -210,7 +210,7 @@ def visit_Arel_Nodes_SelectCore o
         visit o.froms  if @cacheable
         visit o.wheres if @cacheable
         visit o.source if @cacheable
-        # skip o.projections
+        @cacheable = o.projections.none?{ |projection| projection.to_s =~ /distinct/i } unless o.projections.empty?
       end
 
       def visit_Arel_Nodes_SelectStatement o

diff --git a/spec/lib/strategy/unique_index_on_id_cache_spec.rb b/spec/lib/strategy/unique_index_on_id_cache_spec.rb
@@ -99,6 +99,10 @@
     it "should not use the cache when a join clause is used" do
       expect{ Apple.where(:id => [1,2]).joins(:store).all }.to_not use_cache(Apple).on(:id)
     end
+
+    it "should not use the cache when distinct is used in a select" do
+      expect{ Apple.select('distinct person_id').where(:id => [1, 2]).all }.not_to hit_cache(Apple).on(:id)
+    end
   end
 
   context "record_change" do