在Postgres中的generate_series上加入提取（日期從DATE）

Question

我試圖在月份的某一天生成累計銷售額（以便我可以在同一圖表上繪製多個月，在Y軸量的累積和），但是當我離開加入到generate_series（1,31），我得到：

d sum 
1 3746.5 
2 5731.5 
3 9258.42 

而我要的是：

d sum 
1 3746.5 
2 5731.5 
3 9258.42 
4 0 
5 0 
... 0 
31 0 

這裏是我的查詢：

SELECT 
    d, 
    SUM (SUM("Amount")) OVER (ORDER BY "CloseDate" ASC) 
FROM 
    salesforce."Opportunity" 
LEFT JOIN generate_series (1, 31) d ON d = EXTRACT (DAY FROM "CloseDate") 
WHERE 
    EXTRACT (MONTH FROM "CloseDate") = EXTRACT (MONTH FROM now()) 
AND EXTRACT (YEAR FROM "CloseDate") = EXTRACT (YEAR FROM now()) 
AND "StageName" = 'Closed Won' 
AND "Type" = 'Renewal' 
GROUP BY 
    "CloseDate", 
    d 

我可以感覺到我做錯了什麼，但我不知道是什麼。任何幫助將不勝感激 - 謝謝！

Answer 1

沒錯。你需要把你的彙總子查詢，並首先從generate_series然後選擇左連接上：

WITH days as (
     select d from generate_series (1, 31) d), 
    aggregates as (
     SELECT 
      EXTRACT (DAY FROM "CloseDate") d, 
      SUM (SUM("Amount")) OVER (ORDER BY "CloseDate" ASC) total 
     FROM 
      salesforce."Opportunity" 
     WHERE 
      EXTRACT (MONTH FROM "CloseDate") = EXTRACT (MONTH FROM now()) 
      AND EXTRACT (YEAR FROM "CloseDate") = EXTRACT (YEAR FROM now()) 
      AND "StageName" = 'Closed Won' 
      AND "Type" = 'Renewal' 
     GROUP BY 
      "CloseDate" 
    ) 
select days.d, aggregates.total 
from days 
left join aggregates on days.d = aggregates.d 
order by days.d; 

最簡單的方法，如果你在一個子查詢放在group by然後最可讀的左連接子查詢到幾天。您也可以添加更多子查詢並加入它們，以便在同一個表中擁有更多的聚合，即使是來自不同的源表。