每个分组分别取两条记录?
select a.kind_code kindcode,b.shop_id,b.shop_name,b.kind_code from
(select kind_code='002' union all select kind_code='010' union all select kind_code='004') a ,v_m_shop b
where a.kind_code=left(b.kind_code,3)
order by a.kind_code,b.shop_id desc
对以上的派生表,每组kindcode取两条记录???如何实现?