如何在單個Teradata查詢中輸出不同的第25，第50和第75百分位數？

Question

我幾個小時就被困在類似的東西上，並在單個Teradata查詢中計算出輸出第25，第50和第75百分位數的雜亂代碼。可以進一步擴展以產生「5分總結」。根據您的人口估計值獲取最小和最大變化靜態值。

某處有人要求一個優雅的方法。分享我的。

下面的代碼：

SELECT MAX(PER_MIN) AS PER_MIN, 
     MAX(PER_25) AS PER_25, 
     MAX(PER_50) AS PER_50, 
     MAX(PER_75) AS PER_75, 
     MAX(PER_MAX) AS PER_MAX 
FROM (SELECT CASE WHEN ROW_NUMBER() OVER(ORDER BY DURATION_MACRO_CURR ASC) = CAST(COUNT(*) OVER() * 0.01 AS INT) THEN DURATION_MACRO_CURR END AS PER_MIN, 
      CASE WHEN ROW_NUMBER() OVER(ORDER BY DURATION_MACRO_CURR ASC) = CAST(COUNT(*) OVER() * 0.25 AS INT) THEN DURATION_MACRO_CURR END AS PER_25, 
      CASE WHEN ROW_NUMBER() OVER(ORDER BY DURATION_MACRO_CURR ASC) = CAST(COUNT(*) OVER() * 0.50 AS INT) THEN DURATION_MACRO_CURR END AS PER_50 
      CASE WHEN ROW_NUMBER() OVER(ORDER BY DURATION_MACRO_CURR ASC) = CAST(COUNT(*) OVER() * 0.75 AS INT) THEN DURATION_MACRO_CURR END AS PER_75 
      CASE WHEN ROW_NUMBER() OVER(ORDER BY DURATION_MACRO_CURR ASC) = CAST(COUNT(*) OVER() * 0.99 AS INT) THEN DURATION_MACRO_CURR END AS PER_MAX 
     FROM PROD_EXP_DL_CVM.PROD_CVM 
     WHERE PW_END_DATE = '2016-10-18' 
    ) BASE 

下面是所需的輸出：

Answer 1

我會做這個使用條件彙總：

select min(DURATION_MACRO_CURR) as min_val, 
     min(case when seqnum/0.25 >= cnt then DURATION_MACRO_CURR end) as 25_percentile, 
     min(case when seqnum/0.50 >= cnt then DURATION_MACRO_CURR end) as 50_percentile, 
     min(case when seqnum/0.75 >= cnt then DURATION_MACRO_CURR end) as 75_percentile, 
     max(DURATION_MACRO_CURR) as max_val 
from (select pc.*, 
      row_number() over (order by DURATION_MACRO_CURR) as seqnum, 
      count(*) over() as cnt 
     from PROD_EXP_DL_CVM.PROD_CVM pc 
     where pc.PW_END_DATE = '2016-10-18' 
    ) pc;