Mysql 集体订货

我有一张这样的桌子：

Brand | Type | Units
Sony | TV | 5
Toshiba | TV | 4
Sony | Radio | 1
Toshiba | Radio | 10

Type | Brand | Units
Radio | Toshiba | 10
Radio | Sony | 1
TV | Sony | 5
TV | Toshiba | 4

我希望它是这样的：

Brand | Type | Units
Sony | TV | 5
Toshiba | TV | 4
Sony | Radio | 1
Toshiba | Radio | 10

Type | Brand | Units
Radio | Toshiba | 10
Radio | Sony | 1
TV | Sony | 5
TV | Toshiba | 4

也就是说，按照类型、品牌基于类型的计数（10+1对5+4）然后根据单位计数（10对1和5对4）进行订购

你认为实现这一目标的最佳方式是什么

我尝试了以下方法，在每个组下添加小计：

select Type, Brand, sum(Units) from mytable
group by Type, Brand, sum(Units) WITH ROLLUP

Type | Brand | sum(Units)
Radio | Toshiba | 10
Radio | Sony | 1
Radio | null | 11
TV | Sony | 5
TV | Toshiba | 4
TV | null | 9
null | null | 20

---

但是我看不到按这些小计排序的方法。

您可以将查询称为子查询，并根据所需的列执行排序

select type, brand, total
from (
select Type, Brand, sum(Units) as total
from mytable
group by Type, Brand, sum(Units) WITH ROLLUP) t
order by type, total desc

---

您希望首先根据类型的总计对其进行排序。在MySQL中，您可以通过显式聚合和

连接来实现这一点：

select tb.*
from (select Type, Brand, sum(Units) as sumunits
      from mytable
      group by Type, Brand
     ) tb join
     (select Type, sum(Units) as sumunits
      from mytable
      group by Type
     ) t
     on tb.type = t.type
order by t.sumunits desc, tb.sumunits desc;

连接到派生表（带别名的子查询）以获取小计。然后你可以按他们点菜。