请问大佬，一下报错改如何修改语句？
当没有用 EXISTS 引入子查询时，在选择列表中只能指定一个表达式

update im100 set im100.stock_qty=im300.stock_qty,im100.cmp_cd=im300.cmp_cd,im100.inp_id='pd100',inp_time='2014-03-13 15:35:45.937' from im100,im300
where im100.stock_qty=( select top 1 * from(select row_number()
over(partition by item_id order by [inp_time] desc) as rownum,*from
(SELECT im300.item_id,im300.inp_time,im300.stock_qty FROM im300,im100
where im300.item_id=im100.item_id and im100.cmp_cd=im300.cmp_cd and im300.stock_qty<>im100.stock_qty)as H1) as H where H.rownum =1)