快捷鍵多個Mysql SUMS在交織的日期範圍內

Question

當我的網站上的用戶登錄時，會爲統計信息執行多個查詢。

SELECT SUM(earnings) FROM stats WHERE date BETWEEN $start_month AND $end_month 
SELECT SUM(earnings) FROM stats WHERE date BETWEEN $start_last_month AND $end_last_month 
SELECT SUM(earnings) FROM stats WHERE date BETWEEN $start_year AND NOW() 
//etc... 

我覺得我被要求它SUM所有這些對單獨的查詢「作弊」 Mysql的引擎。例如，當它計算年收入時，它也在計算該月內的每月收入......但是，無論如何我都會再次查詢它。

有沒有更好的方法讓多個日期範圍交織的SUMS？

Answer 1

其實您可以使用CASE來計算earning。

SELECT SUM(CASE WHEN date BETWEEN $start_month AND $end_month THEN earnings ELSE 0 END), 
     SUM(CASE WHEN date BETWEEN $start_last_month AND $end_last_month THEN earnings ELSE 0 END), 
     SUM(CASE WHEN date BETWEEN $start_year AND NOW() THEN earnings ELSE 0 END) 
FROM stats