Question

让我说我有一个表，存储一段时间内的itemID，Date和total_shipped：

ItemID | Date      | Total_shipped
__________________________________
  1    | 1/20/2000 |   2
  2    | 1/20/2000 |   3
  1    | 1/21/2000 |   5
  2    | 1/21/2000 |   4
  1    | 1/22/2000 |   1
  2    | 1/22/2000 |   7
  1    | 1/23/2000 |   5
  2    | 1/23/2000 |   6

现在，我想基于多个时间段进行汇总。例如，我想知道每两天总共寄出了多少个物品。因此，所需的输出应类似于：

ItemID | Jan20-Jan21 | Jan22-Jan23 | Jan20-Jan23
_____________________________________________
  1    |  7          |  6          |  13
  2    |  7          |  13         |  20

如何以最有效的方式做到这一点我知道我可以进行三个不同的子查询，但是我认为应该有更好的方法。我的真实数据很大，因此需要考虑几个不同的时间段。 e。在我真正的问题中，我想要current_week，last_week，two_weeks_ago，three_weeks_ago，last_month，two_months_ago，Three_months_ago的已发货商品，所以我认为编写7个不同的子查询不是一个好主意。这是我已经可以运行但对于数据库来说非常昂贵的一般想法

WITH 
sq1 as (
SELECT ItemID, sum(Total_shipped) sum1
FROM table
WHERE Date BETWEEN '1/20/2000' and '1/21/2000'
GROUP BY ItemID),
sq2 as (
SELECT ItemID, sum(Total_Shipped) sum2
FROM table
WHERE Date BETWEEN '1/22/2000' and '1/23/2000'
GROUP BY ItemID),
sq3 as(
SELECT ItemID, sum(Total_Shipped) sum3
FROM Table
GROUP BY ItemID)
SELECT ItemID, sq1.sum1, sq2.sum2, sq3.sum3
FROM Table 
JOIN sq1 on Table.ItemID = sq1.ItemID
JOIN sq2 on Table.ItemID = sq2.ItemID
JOIN sq3 on Table.ItemID = sq3.ItemID

Answer 1

我不知道您为什么用多个数据库标记了这个问题。

无论如何，您可以在 oracle 中使用conditional aggregation，如下所示：

select
    item_id, 
    sum(case when "date" between date'2000-01-20' and date'2000-01-21' then total_shipped end) as "Jan20-Jan21",
    sum(case when "date" between date'2000-01-22' and date'2000-01-23' then total_shipped end) as "Jan22-Jan23",
    sum(case when "date" between date'2000-01-20' and date'2000-01-23' then total_shipped end) as "Jan20-Jan23"
from my_table
group by item_id

干杯！

Answer 2

使用FILTER:

select
    item_id, 
    sum(total_shipped) filter (where date between '2000-01-20' and '2000-01-21') as "Jan20-Jan21",
    sum(total_shipped) filter (where date between '2000-01-22' and '2000-01-23') as "Jan22-Jan23",
    sum(total_shipped) filter (where date between '2000-01-20' and '2000-01-23') as "Jan20-Jan23"
from my_table
group by 1

 item_id | Jan20-Jan21 | Jan22-Jan23 | Jan20-Jan23
---------+-------------+-------------+-------------
       1 |           7 |           6 |          13
       2 |           7 |          13 |          20
(2 rows)

Db<>fiddle.

如何根据各种条件进行汇总

2 个答案: