分组统计中某一个字段重复的只统计一次，怎么实现

select product_line,sum(defect_qty),sum(inspect_qty)
from fr_badness
group by product_line

现在就是 sum(defect_qty),sum(inspect_qty)要过滤掉重复的条码，也就是重复的条码只算一次,相同条码的defect_qty和inspect_qty 一定是相同的，不同的分组一定没有相同的条码,如：

product_line barcode defect_qty inspect_qty position create_date
a 1101 2 10 t1 2011-10-11 21:05:09
a 1101 2 10 t2 2011-10-11 21:06:09
a 1102 9 20 t3 2011-10-11 21:07:09
b 1103 3 12 t4 2011-10-11 21:08:09
b 1103 3 12 t5 2011-10-11 21:07:09
a 1101 2 10 t1 2011-10-11 21:09:09
就是a的barcode为1101统计时只计算一次，b也是一样
统计结果应为：
product_line sum(defect_qty) sum(inspect_qty)
a 11 30
b 3 12

select t.product_line,sum(defect_qty),sum(inspect_qty)
from 
  (
  select distinct
  w.product_line ,
  w.barcode ,
  w.defect_qty ,
  w.inspect_qty
  from fr_badness w
  ) t
group by product_line;