计算平均每月消费

时间:2018-11-16 12:54:11

标签: php mysql laravel laravel-4

我正在Laravel 4中进行自我改进的库存管理项目,但无法找出执行平均月消费量(AMC)计算的最佳方法。

我有两个表,即商品表(id,item_name,price)和存货卡id, item_id, qty_in, qty_out,transaction_date),我应该从中得出AMC计算。 / p>

FORMULA = (sum of current month's qty_out + sum of previous two month's qty_out) / 3 

有人可以用纯PHP和mysql来帮助我解决问题吗?

1 个答案:

答案 0 :(得分:2)

例如,您应该能够使用条件聚合来做到这一点

   drop table if exists t;

create table t(item int,qty_out int , dt date);

insert into t values
(1,1,'2018-09-01'),(1,1,'2018-10-01'),(1,1,'2018-11-01');

select item,
         sum(case when year(dt)*12 + month(dt) = year(now()) * 12 + month(now()) then qty_out else 0 end) thismm,
         sum(case when year(dt)*12 + month(dt) = (year(now()) * 12 + month(now()) -1) or
                            year(dt)*12 + month(dt) = (year(now()) * 12 + month(now()) -2) then qty_out else 0 end) last2mm,
         (sum(case when year(dt)*12 + month(dt) = year(now()) * 12 + month(now()) then qty_out else 0 end) +
         sum(case when year(dt)*12 + month(dt) = (year(now()) * 12 + month(now()) -1) or
                            year(dt)*12 + month(dt) = (year(now()) * 12 + month(now()) -2) then qty_out else 0 end)
         ) / 3  amc
from t
where year(dt)*12 + month(dt) >= (year(now()) * 12 + month(now()) -2)
group by item ;
+------+-----------+-------+--------+
| item | thismonth | last2 | amc    |
+------+-----------+-------+--------+
|    1 |         1 |     2 | 1.0000 |
+------+-----------+-------+--------+
1 row in set (0.01 sec)

请注意转换为月数,以简化日期在一年结束时的位置。 当然,如果您希望获得3个月的滚动平均值,那将是另一个问题。