使用MySQL計算每個時間間隔內的記錄數

Question

我有一個MySQL查詢，我正在計算在任何給定小時內（在任何給定日期等），在15分鐘內爲用戶預訂了多少次呼叫時間間隔。因此，到目前爲止，我有：

SELECT 
date_action, 
DATE_FORMAT(date_action, "%i") AS minute, 
CASE 
    WHEN minute(date_action) BETWEEN 0 and 14 THEN '00' 
    WHEN minute(date_action) BETWEEN 15 and 29 THEN '15' 
    WHEN minute(date_action) BETWEEN 30 and 44 THEN '30' 
    WHEN minute(date_action) BETWEEN 45 and 59 THEN '45' 
END AS intervals 
FROM 
clients 
WHERE 
HOUR(date_action) = 09 
AND DAY(date_action) = 15 
AND MONTH(date_action) = 07 
AND YEAR(date_action) = 2013 

這非常適用，因爲它不過是神奇的成分，我缺少的是一個分配給每個區間的呼叫數量的「計數」，因此，例如上面的代碼中產生：

Date_time - Minute - Interval 
2013-07-15 09:54:24 - 54 - 45 
2013-07-15 09:29:32 - 29 - 15 
2013-07-15 09:13:33 - 13 - 00 
2013-07-15 09:53:53 - 53 - 45 
2013-07-15 09:00:49 - 00 - 00 

所以，我有我的分鐘轉換成時間間隔，因爲我只想要回1行每個間隔，然後已追加到它在該區間的調用次數的計數列，即

Interval - Count 
45 - 2 
15 - 1 
00 - 2 

我覺得我已經撞在這一塊磚牆上我的頭撞得太久了，所以任何幫助將不勝感激。雖然在查詢之後進行了一些後處​​理，但如果可能的話，我寧願在SQL中完成所有這些操作。 :)

Answer 1

您可以按間隔分組並選擇計數。

SELECT 
    count(date_action) as count, 
    CASE 
     WHEN minute(date_action) BETWEEN 0 and 14 THEN '00' 
     WHEN minute(date_action) BETWEEN 15 and 29 THEN '15' 
     WHEN minute(date_action) BETWEEN 30 and 44 THEN '30' 
     WHEN minute(date_action) BETWEEN 45 and 59 THEN '45' 
    END AS intervals 
FROM 
    clients 
WHERE 
    HOUR(date_action) = 09 
    AND DAY(date_action) = 15 
    AND MONTH(date_action) = 07 
    AND YEAR(date_action) = 2013 
    AND rep_id = 28 
GROUP BY intervals 

Answer 2

select period, Sum(NumberOfTimes) as NumberOfTimes 
From 
(Select minute(date_action) % 15 as period, 1 as NumberOfTimes 
From Clients 
WHERE 
    HOUR(date_action) = 09 
    AND DAY(date_action) = 15 
    AND MONTH(date_action) = 07 
    AND YEAR(date_action) = 2013 
    AND rep_id = 28 
) dummyName 
Group By period 

將是另一種方式

％是模運算符