select a.goods_id id,g.name,g.weight,a.total
from
(select goods_id, sum(count) total
from trans
group by goods_id) a 
inner join
goods g
on g.id=a.goods_id
where a.total>19 and g.weight<50
order by g.id

  • 先聚合得到商品的销售数
  • 然后连接表并进行筛选