关于重复记录的的更改,该怎么解决

关于重复记录的的更改
有表 T 结构如下:
  id name qty
  1 a 10
  2 b 20
  3 c 40
  4 a 10
现在想更改如下:
  id name qty
  1 a 10
  2 b 20
  3 c 40
  4 a 0
请高手指教!最好能附上代码,谢
 


[解决办法]

SQL code

-- tryupdate yourTable   set qty = 0 where id in (select id                from (select t.*,                             row_number() over(partition by name, qty order by id) rn                        from yourTable t)               where rn <> 1)
[解决办法]
SQL code
-- TRY IT ..UPDATE TT T1   SET QTY = 0 WHERE EXISTS (SELECT 1          FROM TT T2         WHERE T1.NAME = T2.NAME           AND T1.ID > T2.ID);