从中取出所有nck相同的hweight的值，是更新到所有nck相同的数据的hweight2字段中么？ 这个是更新所有数据的hweight2为hweight的累加。 update tab a set hweight2=(select sum(hweight) from tab b where a.nck=b.nck group by nck); 更新hweigh...
select sum(余额) from 表名
