PostgreSQL - 显示上一年的数据+当年的一周

Question

我需要创建一个列来显示前一年的利润，直到给定年份的一周。 因此，它将以周为单位划分当前年份，并显示给定周的利润是多少。 为了更清楚，假设上一年的利润是 1000。今年第一周的利润是 100，第二周的利润是 200，三分之二，周 -100（亏损）等等。 所以它应该是这样的：

week1|week2|week3|
1100 |1300 |1200 |

我尝试的是：

SELECT
CASE when f1.year = DATE_PART('year', now()) THEN f1.week END as week,
profit as profit
FROM (
SELECT 
DATE_PART('week', so.date_order) as week,
DATE_PART('year', so.date_order) as year,
so.profit as profit
FROM
sale_order as so
GROUP BY
week, year, profit
WHERE
so.date_order >= date_trunc('year', now() - '1 year'::interval)::timestamp::date  and so.date_order <= date_trunc('year', now()+ '1 year'::interval)::timestamp::date-1 
)as f1
GROUP BY
week, profit
ORDER BY
week

但这并没有按我的需要工作，因为它会在每个给定的星期分配利润。我的意思是它只显示那周的利润，但我需要“那周的利润”+“前几年的利润”。

我的查询尝试窗口函数：

(
SELECT
x.id as id,week as week, x.last_year_profit + y.running_profit as week_profit
FROM
(
SELECT
min(sol.id) as id,
 --DATE_PART('year',  so.date_order) AS calcyear, DATE_PART('week',  so.date_order) AS calcweek,
sum(sol.price_subtotal - (CASE WHEN sol.account_cost_amount != 0 THEN sol.account_cost_amount ELSE sol.purchase_price END )) as last_year_profit
-- sum(sol.price_subtotal) as price_unit, sum(sol.purchase_price) as purchase_price, sum(sol.account_cost_amount) as account_cost_amount
FROM
sale_order as so
INNER JOIN sale_order_line as sol ON (sol.order_id = so.id)
INNER JOIN res_partner as rp ON (so.partner_id = rp.id)
WHERE EXISTS (
SELECT * FROM  res_partner_category_rel rpcl
WHERE 
rpcl.partner_id=rp.id and rpcl.category_id=37
and (so.date_order >= date_trunc('year', now() - '1 year'::interval)::timestamp::date  and so.date_order <= date_trunc('year', now())::timestamp::date-1 )
and so.state != 'cancel'
)
) as x
CROSS JOIN (
SELECT
date_trunc('week', so.date_order) as week,
sum(sum(sol.price_subtotal - (CASE WHEN sol.account_cost_amount != 0 THEN sol.account_cost_amount ELSE sol.purchase_price END ))) OVER  ( ORDER BY date_trunc('week', so.date_order)) as running_profit

FROM
sale_order as so
INNER JOIN sale_order_line as sol ON (sol.order_id = so.id)
INNER JOIN res_partner as rp ON (so.partner_id = rp.id)
WHERE EXISTS (
SELECT * FROM  res_partner_category_rel rpcl
WHERE 
rpcl.partner_id=rp.id and rpcl.category_id=37
AND so.date_order >= date_trunc('year', now())::timestamp::date
AND    so.date_order <  date_trunc('year', now() + '1 year'::interval)::timestamp::date 
and so.state != 'cancel'
)
GROUP BY
week
) as y
GROUP BY
id, week,week_profit
) as f1

由于某种原因，它不会在几周内拆分利润，而是只显示一行总计，如下所示：

week    |week_profit|
20130114| 1500       |

Answer 1

运行总和的基本查询

使用众所周知的聚合函数sum() 作为window function。

SELECT week, x.last_year_profit + y.running_profit AS week_profit
FROM (         -- total last year
   SELECT sum(profit) AS last_year_profit
   FROM   sale_order
   WHERE  date_order >= date_trunc('year', now() - interval '1 year')
   AND    date_order <  date_trunc('year', now()) 
   ) x
CROSS JOIN (   -- running sum current year
   SELECT date_trunc('week', date_order) AS week
         ,sum(sum(profit)) OVER (ORDER BY date_trunc('week', date_order))
                                                        AS running_profit
   FROM   sale_order
   WHERE  date_order >= date_trunc('year', now() - interval '1 year')
   AND    date_order <  date_trunc('year', now() + interval '1 year')
   GROUP  BY 1
   ) y;

结果：

week       | week_profit
-----------+------------
2012-01-02 | 1100
2012-01-09 | 1300
2012-01-16 | 1200
...

这里的高级功能是我将 window 和 聚合函数 组合在单个查询级别中 - 即使在单个表达式中（！），导致 SELECT项目，这可能会让无辜的眼睛感到惊讶：

sum(sum(profit)) OVER (ORDER BY date_trunc('week', date_order))

在这个密切相关的答案中找到有关其工作原理的详细说明：
Postgres window function and group by exception

还请注意我在您的查询中改进的多个其他细节。

->SQLfiddle

数组/交叉表（）

在一行中累积所有周的原始方法是将结果聚合到一个数组中：

SELECT ARRAY( 
    SELECT x.last_year_profit + y.running_profit  -- only one column
    FROM (
    -- rest like query above
   ) a

结果：

{1100,1300,1200, ...}

或者，更高级的是，您使用crosstab() 查询，如以下相关答案中所述：
PostgreSQL Crosstab Query

许多相关的 crossbab 答案之一，特别是处理时间数据：
Querying row counts segregated by date ranges