sql相同項求和

 select (SELECT O2.ORG_NAME
           FROM OUTSOURCE_ORG O2
          where o2.org_id = oo.parent_id) net_NAME,
        oo.parent_id,
        sum(oz.line_length) as net_length
 
   from outsource_org oo, outsource_zone_line_length oz
  where oz.line_length is not null
    and oo.org_type = '5'
    and to_char(oo.org_id) = oz.zone_id
 
  group by oo.parent_id
  order by oo.parent_id