Avoid sanitize_sql when we can use Relation#where instead

activerecord/lib/active_record/associations/association_scope.rb

@@ -90,8 +90,11 @@ module ActiveRecord
 
             scope = scope.joins(join(foreign_table, constraint))
 
-            unless conditions.empty?
+            conditions.each do |condition|
-              scope = scope.where(sanitize(conditions, table))
+              condition = interpolate(condition)
+              condition = { (table.table_alias || table.name) => condition } unless i == 0
+
+              scope = scope.where(condition)
             end
           end
         end

activerecord/lib/active_record/associations/join_dependency/join_association.rb

@@ -95,8 +95,11 @@ module ActiveRecord
             conditions = self.conditions[i].dup
             conditions << { reflection.type => foreign_klass.base_class.name } if reflection.type
 
-            unless conditions.empty?
+            conditions.each do |condition|
-              constraint = constraint.and(sanitize(conditions, table))
+              condition = active_record.send(:sanitize_sql, interpolate(condition), table.table_alias || table.name)
+              condition = Arel.sql(condition) unless condition.is_a?(Arel::Node)
+
+              constraint = constraint.and(condition)
             end
 
             relation.from(join(table, constraint))

activerecord/lib/active_record/associations/join_helper.rb

@@ -40,16 +40,6 @@ module ActiveRecord
       def join(table, constraint)
         table.create_join(table, table.create_on(constraint), join_type)
       end
-
-      def sanitize(conditions, table)
-        conditions = conditions.map do |condition|
-          condition = active_record.send(:sanitize_sql, interpolate(condition), table.table_alias || table.name)
-          condition = Arel.sql(condition) unless condition.is_a?(Arel::Node)
-          condition
-        end
-
-        conditions.length == 1 ? conditions.first : Arel::Nodes::And.new(conditions)
-      end
     end
   end
 end

activerecord/lib/active_record/associations/preloader/association.rb

@@ -95,8 +95,8 @@ module ActiveRecord
         def build_scope
           scope = klass.scoped
 
-          scope = scope.where(process_conditions(options[:conditions]))
+          scope = scope.where(interpolate(options[:conditions]))
-          scope = scope.where(process_conditions(preload_options[:conditions]))
+          scope = scope.where(interpolate(preload_options[:conditions]))
 
           scope = scope.select(preload_options[:select] || options[:select] || table[Arel.star])
           scope = scope.includes(preload_options[:include] || options[:include])
@@ -112,13 +112,11 @@ module ActiveRecord
           scope
         end
 
-        def process_conditions(conditions)
+        def interpolate(conditions)
           if conditions.respond_to?(:to_proc)
-            conditions = klass.send(:instance_eval, &conditions)
+            klass.send(:instance_eval, &conditions)
-          end
+          else
-
+            conditions
-          if conditions
-            klass.send(:sanitize_sql, conditions)
           end
         end
       end