累积天数

Question

我有一个MySQL表,如下所示:

date         count
2010-01-01   5
2010-01-02   6
2010-01-03   7

我怎样才能将每一天的总和积累到下一个？结果如下:

date         acum per day
2010-01-01   5
2010-01-02   11
2010-01-03   18

我想我需要一些(每个日期)......但没有任何线索.

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只是我在Eric的回答后使用的最终查询.(谢谢).

SELECT t1.dia,sum(t2.operacions),sum(t2.amount)FROM

(SELECT count(*) operations, sum(amount), date(b.timestamp) dia
    FROM transactions b group by date(b.timestamp)) t1 

INNER JOIN 

(SELECT count(*) operations, sum(amount), date(b.timestamp) dia
    FROM transactions b group by date(b.timestamp)) t2 

ON t2.dia <= t1.dia GROUP BY t1.dia

Answer 1

嗯,我认为这会有效,但不确定性能如何:

SELECT t1.date, sum(t2.count)
FROM mytable t1 INNER JOIN mytable t2 ON t2.date <= t1.date
GROUP BY t1.date