SQL：動態日期創建問題

Question

需要建議以使其動態於日期。

預期：日期，總賣家，上一日期的賣家

當前：表格中的數據（active_seller_codes）：日期，seller_code

查詢：-明智的日期賣方計數

select date,count(distinct seller_code) as Sellers_COunt  
from active_seller_codes where date between '2016-12-15' AND '2016-12-15'

-前幾天的賣家

select date,count(distinct seller_code) as Last_Day_Seller  
from active_seller_codes 
where date between '2016-12-15' AND '2016-12-15'
  and seller_code IN(
    select seller_code from active_seller_codes 
    where date between '2016-12-14' AND '2016-12-14'
  )
group by 1

數據庫使用：Vertica

Answer 1

專心閱讀，您似乎想要報表中的一行，前兩列中包含搜索日期的數據，第三列和第四列中包含搜索日期前一天的數據，如下所示：

sales_date|sellers_count|prev_date |prev_sellers_count
2016-12-15|            8|2016-12-14|                 5

解決方案可能是這樣的（沒有第一個通用表表達式，在我的情況下，它包含數據，但是在您的情況下，數據將在您的active_seller_codes表中。

WITH
-- initial input
  (sales_date,seller_code) AS (
          SELECT DATE '2016-12-15',42
UNION ALL SELECT DATE '2016-12-15',43
UNION ALL SELECT DATE '2016-12-15',44
UNION ALL SELECT DATE '2016-12-15',45
UNION ALL SELECT DATE '2016-12-15',46
UNION ALL SELECT DATE '2016-12-15',47
UNION ALL SELECT DATE '2016-12-15',48
UNION ALL SELECT DATE '2016-12-15',49
UNION ALL SELECT DATE '2016-12-14',42
UNION ALL SELECT DATE '2016-12-14',44
UNION ALL SELECT DATE '2016-12-14',46
UNION ALL SELECT DATE '2016-12-14',48
UNION ALL SELECT DATE '2016-12-14',50
UNION ALL SELECT DATE '2016-12-13',42
UNION ALL SELECT DATE '2016-12-13',43
UNION ALL SELECT DATE '2016-12-13',44
UNION ALL SELECT DATE '2016-12-13',45
UNION ALL SELECT DATE '2016-12-13',46
UNION ALL SELECT DATE '2016-12-13',47
UNION ALL SELECT DATE '2016-12-13',48
UNION ALL SELECT DATE '2016-12-13',49
)
,
-- search argument this, in the real query, would come just after the WITH keyword
-- as the above would be the source table
search_dt(search_dt) AS (SELECT DATE '2016-12-15')
,
-- the two days we're interested in, de-duped
distinct_two_days AS (
SELECT DISTINCT
  sales_date
, seller_code
FROM active_seller_codes
WHERE sales_date IN (
    SELECT           search_dt     FROM search_dt -- the search date
    UNION ALL SELECT search_dt - 1 FROM search_dt -- the day before
  )
)
,    
-- the two days we want one above the other,
-- with index for the final pivot
vertical AS (
SELECT
  ROW_NUMBER() OVER (ORDER BY sales_date DESC) AS idx
, sales_date
, count(DISTINCT seller_code) AS seller_count
FROM distinct_two_days
GROUP BY 2
)
SELECT
  MAX(CASE idx WHEN 1 THEN sales_date   END) AS sales_date
, SUM(CASE idx WHEN 1 THEN seller_count END) AS sellers_count
, MAX(CASE idx WHEN 2 THEN sales_date   END) AS prev_date
, SUM(CASE idx WHEN 2 THEN seller_count END) AS prev_sellers_count
FROM vertical
;    


sales_date|sellers_count|prev_date |prev_sellers_count
2016-12-15|            8|2016-12-14|                 5