动态日期查询

Question

我即将弄清楚如何根据当前月份与前一年的同月计算商品的价格差异，但我目前使用的是静态日期。

理想情况下，无论第一个 table 的发票月份是什么，我都希望它是动态的，它会查看上一年同月的匹配项目交易。

请注意，由于我想使用当前月份的发票日期来驱动折线图，因此我需要将其添加到我的第一个 table 但是，我宁愿不按它分组，因为我认为它可能会扭曲我的数字。

示例数据存储在这里：https://drive.google.com/file/d/1hAVfDwNw9pNDS9-Nc6U3eafaHb_2pL6f/view?usp=sharing

在上面的数据集中，我会寻找以下结果：

output

我理想的最终输出是

Inv 日期价格差异 2020 年 6 月 | -.011683918 2020 年 7 月 | .046218968

WITH cur ([cur_item],[cur_price],[cur_extprice],[cur_volume],[cur_avgprice])

AS

(
SELECT
    inv_item_mst.item AS [cur_item],
    SUM(inv_item_mst.price) AS [cur_price],
    SUM(inv_item_mst.price*inv_item_mst.qty_invoiced) AS [cur_extprice],
    SUM(inv_item_mst.qty_invoiced) AS [cur_volume],
    SUM(inv_item_mst.price*inv_item_mst.qty_invoiced)/NULLIF(SUM(inv_item_mst.qty_invoiced),0) AS [cur_avgprice]

FROM inv_item_mst

LEFT JOIN inv_hdr_mst
    ON inv_item_mst.inv_num=inv_hdr_mst.inv_num
LEFT JOIN customer_mst
    ON inv_hdr_mst.cust_num=customer_mst.cust_num AND inv_hdr_mst.cust_seq=customer_mst.cust_seq

WHERE YEAR(inv_hdr_mst.inv_date)=YEAR(GETDATE()) and MONTH(inv_hdr_mst.inv_date)=MONTH('3/1/2020') 

GROUP BY inv_item_mst.item

)

,

prev ([prev_item],[prev_price],[prev_extprice],[prev_volume],[prev_avgprice])

AS

(
SELECT
    inv_item_mst.item AS [prev_item],
    SUM(inv_item_mst.price) AS [prev_price],
    SUM(inv_item_mst.price*inv_item_mst.qty_invoiced) AS [prev_extprice],
    SUM(inv_item_mst.qty_invoiced) AS [prev_volume],
    SUM(inv_item_mst.price*inv_item_mst.qty_invoiced)/NULLIF(SUM(inv_item_mst.qty_invoiced),0) AS [prev_avgprice]

FROM inv_item_mst

LEFT JOIN inv_hdr_mst
    ON inv_item_mst.inv_num=inv_hdr_mst.inv_num
LEFT JOIN customer_mst
    ON inv_hdr_mst.cust_num=customer_mst.cust_num AND inv_hdr_mst.cust_seq=customer_mst.cust_seq

WHERE YEAR(inv_hdr_mst.inv_date)=YEAR(GETDATE())-1 and MONTH(inv_hdr_mst.inv_date)=MONTH('3/1/2019')
GROUP BY inv_item_mst.item

)

SELECT
cur.cur_item,
CASE
WHEN cur.cur_volume IS NULL
THEN 0
ELSE (cur.cur_avgprice - prev.prev_avgprice)/cur.cur_volume
END AS [price_variance]

from cur

LEFT JOIN prev
    ON cur.cur_item=prev.prev_item

Answer 1

低于您的预期结果吗？

Month  | Price Variance
6      | -0.011683
7      | -0.056540

July 2020 | .046218968

当前是 2019 年 7 月，上一个是 2020 年 7 月。这不正确吗？

您的数据库是 SQL 服务器，对吗？

作为一种简单的方法，您可以使用CASE表达式来计算当年和上一年的数据。

with cte as (
select
  item,
  format(max(inv_date), 'MM/yyy') as month,
  sum(case when year(inv_date)=year(getdate()) then price end) as cur_price,
  sum(case when year(inv_date)=year(getdate()) then price*qty_invoiced end) as cur_extprice,
  sum(case when year(inv_date)=year(getdate()) then qty_invoiced end) as cur_volume,
  sum(case when year(inv_date)=year(getdate()) then 1.0*price*qty_invoiced end)/sum(case when year(inv_date)=year(getdate()) then qty_invoiced end) as cur_avgprice,
  sum(case when year(inv_date)=year(getdate())-1 then price end) as prev_price,
  sum(case when year(inv_date)=year(getdate())-1 then price*qty_invoiced end) as prev_extprice,
  sum(case when year(inv_date)=year(getdate())-1 then qty_invoiced end) as prev_volume,
  sum(case when year(inv_date)=year(getdate())-1 then 1.0*price*qty_invoiced end)/sum(case when year(inv_date)=year(getdate())-1 then qty_invoiced end) as prev_avgprice
from inv_item_mst
group by item, month(inv_date)
)
select
  month,
  sum((1.0*cur_avgprice - prev_avgprice)/cur_volume) as cur_price_variance,
  sum((1.0*prev_avgprice - cur_avgprice)/prev_volume) as prev_price_variance
from cte
group by month;

dbfiddle

另一个具有相同结果的查询如下：

with
cte1 as (
  select
    inv_date,
    year(inv_date) as year,
    month(inv_date) as month,
    item,
    cust,
    qty_invoiced as cur_qty_invoiced,
    price as cur_price,
    cast(NULL as int) as prev_qty_invoiced,
    cast(NULL as int) as prev_price
  from inv_item_mst
  where year(inv_date)=year(getdate())
  union all
  select
    inv_date,
    year(inv_date),
    month(inv_date),
    item,
    cust,
    NULL,
    NULL,
    qty_invoiced,
    price
  from inv_item_mst
  where year(inv_date)=year(getdate())-1
),
cte2 as (
  select
    item,
    month,
    sum(cur_price) as cur_price,
    sum(cur_price*cur_qty_invoiced) as cur_extprice,
    sum(cur_qty_invoiced) as cur_volume,
    sum(1.0*cur_price*cur_qty_invoiced)/sum(cur_qty_invoiced) as cur_avgprice,
    sum(prev_price) as prev_price,
    sum(prev_price*prev_qty_invoiced) as prev_extprice,
    sum(prev_qty_invoiced) as prev_volume,
    sum(1.0*prev_price*prev_qty_invoiced)/sum(prev_qty_invoiced) as prev_avgprice
  from cte1
  group by item, month
)
select
  month,
  sum((1.0*cur_avgprice - prev_avgprice)/cur_volume) as cur_price_variance
from cte2
group by month;

cte1 使用 UNION 每年都有不同的列。
cte2 具有按项目和不带年份的月份分组的聚合。
最后一个查询有每个月的汇总。

dbfiddle

动态日期查询

Dynamic Date Lookup

sql

date

variance