數與組和由

Question

可能重複：
Calculate a running total in MySQL

我需要它爲每個dates.Now的分組數之我正在以下查詢和獲取了放如下：

SELECT `timestamp` , COUNT(*) 
FROM `A` 
WHERE `timestamp` >= '2013-01-04 07:12:12' 
GROUP BY DATE_FORMAT(`timestamp` , '%Y-%m-%d') 

和我得到

OUTPUT：

timestamp            count(*) 
-------------------------------------------------- ----------- 
2013-01-04 07:58:21        4 
2013-01-05 09:28:56        38 
2013-01-06 00:03:04        10 

現在我需要的是，我需要獲得通過日期分組計數的總和。這是第二次約會應該是42，第三次約會應該是52.我如何在查詢中做到這一點？

Answer 1

你可以試試下面的SQL

SELECT DATE_FORMAT(ts_date , '%Y-%m-%d') as ts_dt_out, SUM(cnt) 
FROM 
(
SELECT `timestamp` ts_date , COUNT(*) as cnt 
FROM `A` 
WHERE `timestamp` >= '2013-01-04 07:12:12' 
GROUP BY DATE_FORMAT(`timestamp` , '%Y-%m-%d') 
) 
as inner 
WHERE ts_date >= '2013-01-04 07:12:12' 
GROUP BY ts_dt_out 

注：未測試讓我知道，如果它不工作

Answer 2

試試看：

SELECT `timestamp` , @sum:= ifnull(@sum, 0) + COUNT(*) 
FROM `A` 
WHERE `timestamp` >= '2013-01-04 07:12:12' 
GROUP BY DATE_FORMAT(`timestamp` , '%Y-%m-%d') 

Answer 3

嘗試：

SELECT 
    timestamp t , 
    (select count(*) from A where timestamp <= t) 
FROM A 
GROUP BY timestamp 
ORDER BY timestamp 

Answer 4

這裏是一個簡單的方法

SELECT 
    `timestamp` , 
    COUNT(*) 
FROM `A` 
WHERE `timestamp` >= '2013-01-04 07:12:12' 
GROUP BY DATE(`timestamp`)