將多個MySQL查詢合併爲一個

Question

我試圖編寫一個查詢，我可以每隔3個月在一個數據庫的事務表中獲得不同的user_id。

我可以手動實現的結果，如果我這樣做

SELECT COUNT(DISTINCT(user_id)) FROM transactions WHERE DATE(created_at) BETWEEN "2011-01-01" AND "2011-03-31". 

但是，如果我想在幾年的季度期間的自動運行這個它會永遠需要。

有沒有辦法在單個查詢中包裝這種東西？

Answer 1

SELECT COUNT(DISTINCT user_id),YEAR(created_at), QUARTER(created_at) 
FROM transactions 
GROUP BY YEAR(created_at), QUARTER(created_at) 

Answer 2

這會做你在問什麼？

select user_id, year(created_at) as `year`, quarter(created_at) as `quarter`, count(*) 
from transactions 
group by user_id, year(created_at), quarter(created_at) 

Answer 3

什麼是這樣的：

SELECT COUNT(DISTINCT USER_ID), 
     QUARTER(created_at), 
     YEAR(created_at)  
    FROM transactions 
GROUP BY YEAR(created_at), QUARTER(created_at);