我有这样的数据 表 t_prod
+---------+----------+-------------+-----------+----------+
|t_prod_id|t_prod_lot|t_prod_sublot|t_prod_card|t_prod_qty|
+---------+----------+-------------+-----------+----------+
| 4 | R001 | 1 | 1 | 6000 |
| 5 | R001 | 1 | 2 | 6000 |
| 6 | R001 | 1 | 3 | 6000 |
| 10 | R001 | 1 | 4 | 6000 |
| 11 | R001 | 1 | 5 | 6000 |
| 12 | R001 | 1 | 6 | 6000 |
| 13 | R001 | 2 | 1 | 6000 |
| 34 | R001 | 2 | 2 | 6000 |
| 36 | R001 | 2 | 3 | 2000 |
+---------+----------+-------------+-----------+----------+
当我选择 t_prod_lot = R001 时，我想要这样的结果。当 t_prod_sublot 值相同时计数 t_prod_sublot，当 t_prod_sublot 值相同时求和 t_prod_qty
+---------+----------+-------------+-----------+----------+--------------------+---------------+
|t_prod_id|t_prod_lot|t_prod_sublot|t_prod_card|t_prod_qty|count(t_prod_sublot)|sum(t_prod_qty)|
+---------+----------+-------------+-----------+----------+--------------------+---------------+
| 4 | R001 | 1 | 1 | 6000 | 6 | 36000 |
| 5 | R001 | 1 | 2 | 6000 | 6 | 36000 |
| 6 | R001 | 1 | 3 | 6000 | 6 | 36000 |
| 10 | R001 | 1 | 4 | 6000 | 6 | 36000 |
| 11 | R001 | 1 | 5 | 6000 | 6 | 36000 |
| 12 | R001 | 1 | 6 | 6000 | 6 | 36000 |
| 13 | R001 | 2 | 1 | 6000 | 3 | 14000 |
| 34 | R001 | 2 | 2 | 6000 | 3 | 14000 |
| 36 | R001 | 2 | 3 | 2000 | 3 | 14000 |
+---------+----------+-------------+-----------+----------+--------------------+---------------+
生成此结果的查询是什么？ Sql Fiddle
最佳答案
下面是一个选项，它使用带有子查询的join 来count 和sum 值:
select *
from t_prod t join (
select t_prod_lot, t_prod_sublot,
count(t_prod_card) t_prod_card_cnt,
sum(t_prod_qty) t_prod_qty_sum
from t_prod
group by t_prod_lot, t_prod_sublot
) t2 on t.t_prod_lot = t2.t_prod_lot and t.t_prod_sublot = t2.t_prod_sublot
关于mysql - 自加入总和字段，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38965820/