Question

可能重复：
Calculate a running total in MySQL

我需要得到为每个日期分组的计数总和。现在我运行以下查询并按如下方式获取输出：

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

我正在

输出：

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

现在我需要的是，我需要得到按日期分组的总数。那是第二个日期应该是42，第三个日期应该是52.如何在查询中执行此操作？

Answer 1

你可以尝试下面的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

注意：未经测试让我知道它是否不起作用

Answer 2

试一试：

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

尝试：

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

Answer 4

这是一个简单的方法

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

和组的总数

4 个答案: