Postgres的查詢銷售計劃

Question

=================

這是我的查詢：

SELECT 
SUM(sub_total) AS sales, 
CASE WHEN (sub_total<100) THEN '0-99'  
    WHEN (sub_total>=100 AND sub_total<200) THEN '100-199' 
    WHEN (sub_total>=200 AND sub_total<300) THEN '200-299' 
    WHEN (sub_total>=300 AND sub_total<400) THEN '300-399' 
    WHEN (sub_total>=400 AND sub_total<500) THEN '400-499' 
    ELSE '500+' 
END 
AS product_sales_range 
FROM order_item 
GROUP BY sub_total 

========= ===============

它給人的ressult爲：

sales  product_sales_range 
-----  ------------------- 

10398.96  200-299 
600   100-199 
300   0-99 
7699.78  300-399 
6799.32  100-199 
600   0-99 
26599.24  500+ 

================== ========================

我希望得到的結果是這樣的：

sales  product_sales_range sales_increase_by_10% sales_increase_by_20% 
-----  ------------------- ------------------ ------------------ 

10398.96  200-299 
600   100-199 
300   0-99 
7699.78  300-399 
6799.32  100-199 
600   0-99 
26599.24  500+ 

============

要求：

目前我們的銷售數字。需要找出銷售預測，就像銷售額增加10％，20％，30％等一樣。例如：今天sales_sales_range（0-99）的銷售額是300.如果銷售額增加10％，sales_increase_by_10 ％應該是330

Answer 1

我失去了一些東西，或者你只需​​要使用：

SELECT SUM(sub_total) AS sales, 
     CASE WHEN (sub_total<100) THEN '0-99' 
       WHEN (sub_total>=100 AND sub_total<200) THEN '100-199' 
       WHEN (sub_total>=200 AND sub_total<300) THEN '200-299' 
       WHEN (sub_total>=300 AND sub_total<400) THEN '300-399' 
       WHEN (sub_total>=400 AND sub_total<500) THEN '400-499' 
       ELSE '500+' 
     END AS product_sales_range, 
     SUM(sub_total) * 1.1 AS sales_increase_by_10Percent, 
     SUM(sub_total) * 1.2 AS sales_increase_by_20Percent 
    FROM order_item 
GROUP BY sub_total