分配類別

Question

假設我有一個這樣的表：

CampaignId Category Strike 
    1   A   2 
    1   B   3 
    1   Others  5 
    2   A   4 
    2   B   2 
    3   C   1 
    3   C   4 
    4   A   1 
    4   B   1 
    4   C   1 
    4   D   1 
    4   Others  1 

然後，我會計算每個Category的Strike百分比CampaignId這樣的：

SELECT CampaignId, Category, Strike, (SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId)/SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId, Category) * 100) AS PercentageOfStrikesByCategoryByCampaignId 
FROM myTable 

造成中間表如下：

CampaignId Category Strike PercentageOfStrikesByCategoryByCampaignId 
    1   A   2  20.0 
    1   B   3  30.0 
    1   Others  5  50.0 
    2   A   4  66.6 
    2   B   2  33.3 
    3   C   1  20.0 
    3   C   4  80.0 
    4   A   1  20.0 
    4   B   1  20.0 
    4   C   1  20.0 
    4   D   1  20.0 
    4   Others  1  20.0 

現在，我想根據上面計算的PercentageOfStrikesByCategoryByCampaignId分配一個最終標籤，說FinalCategory。 FinalCategory的標準要點是：如果每個CampaignId中的其中一個類別爲'其他'AND爲PercentageOfStrikesByCategoryByCampaignId >= 30.0，則該CampaignId組中的其餘行將標記爲'其他'。否則，我們將Category直接複製到FinalCategory。結果表應該如下所示：

CampaignId Category Strike PercentageOfStrikesByCategoryByCampaignId FinalCategory 
    1   A   2  20.0          Others 
    1   B   3  30.0          Others 
    1   Others  5  50.0          Others 
    2   A   4  66.6          A 
    2   B   2  33.3          B 
    3   C   1  20.0          C 
    3   C   4  80.0          C 
    4   A   1  20.0          A 
    4   B   1  20.0          B 
    4   C   1  20.0          C 
    4   D   1  20.0          D 
    4   Others  1  20.0          Others 

我該如何使用盡可能簡單的SQL查詢來實現這樣的事情？預先感謝您的幫助！

Answer 1

SELECT CampaignId, Category, Strike, PercentageOfStrikesByCategoryByCampaignId, 
CASE WHEN Others_count > 0 AND 
    MAX(CASE WHEN Category='Others' THEN PercentageOfStrikesByCategoryByCampaignId END) OVER (PARTITION BY CampaignId) >= 30 THEN 'Others' 
ELSE Category END AS FinalCategory 
FROM (
SELECT CampaignId, Category, Strike, 
(SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId) 
/SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId, Category) * 100) AS PercentageOfStrikesByCategoryByCampaignId 
,SUM(CASE WHEN Category='Others' THEN 1 ELSE 0 END) OVER (PARTITION BY CampaignId) as Others_count 
FROM myTable 
) T 

添加到現有的查詢中

• Others_Count爲與sum窗口函數每個CAMPAIGNID
• 使用case的表達與計算Others_Count和max窗口功能，如果要檢查的行與Others類別具有> = 30的百分比，並將'其他'指定爲最終類別，否則按原樣使用該類別。

Answer 2

讓我們先從你的查詢作爲CTE或子查詢：

WITH t as (
     SELECT CampaignId, Category, Strike, 
      (SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId)/SUM(Strike::FLOAT) OVER (PARTITION BY CampaignId, Category) * 100) AS PercentageOfStrikesByCategoryByCampaignId 
     FROM myTable 
    ) 
select t.*, 
     (case when OthersFlag = 1 then 'Others' else category end) as FinalCategory 
from (select t.*, 
      sum(case when category = 'Others' and PercentageOfStrikesByCategoryByCampaignId > 30.0 then 1 else 0 end) over 
       (partition by campaignid) as OthersFlag 
     from t 
    ) t;