Fix unknown attribute reference error

Author: MarkSiemers-msr

lib/job-iteration/active_record_batch_enumerator.rb

@@ -29,7 +29,7 @@ def initialize(relation, columns: nil, batch_size: 100, cursor: nil)
         raise JobIteration::ActiveRecordCursor::ConditionNotSupportedError
       end
 
-      @base_relation = relation.reorder(@columns.join(","))
+      @base_relation = relation.reorder(Arel.sql(@columns.join(",")))
     end
 
     def each

lib/job-iteration/active_record_cursor.rb

@@ -30,7 +30,7 @@ def initialize(relation, columns, position = nil)
         raise ConditionNotSupportedError
       end
 
-      @base_relation = relation.reorder(*@columns)
+      @base_relation = relation.reorder(Arel.sql(@columns.join(",")))
       @reached_end = false
     end