Merge pull request #904 from reamaze/remove-redundant-join

tags_count only need to join on the taggable's table if using STI

CHANGELOG.md

@@ -4,6 +4,10 @@ Each change should fall into categories that would affect whether the release is
 
 As such, a _Feature_ would map to either major or minor. A _bug fix_ to a patch.  And _misc_ is either minor or patch, the difference being kind of fuzzy for the purposes of history.  Adding tests would be patch level.
 
+### [6.0.1 / 2018-06-27](https://github.com/mbleigh/acts-as-taggable-on/compare/v6.0.0...v6.0.1)
+  * Fixes
+    * [@hengwoon tags_count only need to join on the taggable's table if using STI ](https://github.com/mbleigh/acts-as-taggable-on/pull/904)
+
 ### [6.0.0 / 2018-06-19](https://github.com/mbleigh/acts-as-taggable-on/compare/v5.0.0...v6.0.0)
   * Breaking Changes
    * [@Fodoj Drop support for Rails 4.2](https://github.com/mbleigh/acts-as-taggable-on/pull/887)

lib/acts_as_taggable_on/taggable/collection.rb

@@ -94,16 +94,18 @@ def all_tag_counts(options = {})
         ## Generate conditions:
         options[:conditions] = sanitize_sql(options[:conditions]) if options[:conditions]
 
-        ## Generate joins:
-        taggable_join = "INNER JOIN #{table_name} ON #{table_name}.#{primary_key} = #{ActsAsTaggableOn::Tagging.table_name}.taggable_id"
-        taggable_join << " AND #{table_name}.#{inheritance_column} = '#{name}'" unless descends_from_active_record? # Current model is STI descendant, so add type checking to the join condition
-
         ## Generate scope:
         tagging_scope = ActsAsTaggableOn::Tagging.select("#{ActsAsTaggableOn::Tagging.table_name}.tag_id, COUNT(#{ActsAsTaggableOn::Tagging.table_name}.tag_id) AS tags_count")
         tag_scope = ActsAsTaggableOn::Tag.select("#{ActsAsTaggableOn::Tag.table_name}.*, #{ActsAsTaggableOn::Tagging.table_name}.tags_count AS count").order(options[:order]).limit(options[:limit])
 
-        # Joins and conditions
-        tagging_scope = tagging_scope.joins(taggable_join)
+        # Current model is STI descendant, so add type checking to the join condition
+        unless descends_from_active_record?
+          taggable_join = "INNER JOIN #{table_name} ON #{table_name}.#{primary_key} = #{ActsAsTaggableOn::Tagging.table_name}.taggable_id"
+          taggable_join << " AND #{table_name}.#{inheritance_column} = '#{name}'"
+          tagging_scope = tagging_scope.joins(taggable_join)
+        end
+
+        # Conditions
         tagging_conditions(options).each { |condition| tagging_scope = tagging_scope.where(condition) }
         tag_scope = tag_scope.where(options[:conditions])
 

lib/acts_as_taggable_on/version.rb

@@ -1,4 +1,3 @@
 module ActsAsTaggableOn
-  VERSION = '6.0.0'
+  VERSION = '6.0.1'
 end
-

spec/acts_as_taggable_on/single_table_inheritance_spec.rb

@@ -152,6 +152,11 @@
 
       inheriting_model.update_attributes! name: 'foo'
     end
+
+    it "should only join with taggable's table to check type for inherited models" do
+      expect(TaggableModel.tag_counts_on(:tags).to_sql).to_not match /INNER JOIN taggable_models ON/
+      expect(InheritingTaggableModel.tag_counts_on(:tags).to_sql).to match /INNER JOIN taggable_models ON/
+    end
   end
 
   describe 'ownership' do