我有一个包含两列的表 - 日期金额（使用情况）。我想将我的用法与去年的
进行比较数据
Date Amount
01-01-2015 23
02-01-2015 24
03-01-2015 19
04-01-2015 11
05-01-2015 5
06-01-2015 23
07-01-2015 21
08-01-2015 6
09-01-2015 26
10-01-2015 9
[...]
01-01-2016 30
02-01-2016 19
03-01-2016 5
04-01-2016 8
05-01-2016 15
06-01-2016 27
07-01-2016 19
08-01-2016 21
09-01-2016 24
10-01-2016 27
[until today's date]
sql语句应该返回结果到今天的日期，差异应该是一个运行总计 - 2016年一天的金额减去2015年同一天的金额加上之前的差额。假设今天是1月10日，结果将是：
Day Diff
01-01-2016 7 (30-23)
02-01-2016 2 (19-24+7)
03-01-2016 -12 (5-19+2)
04-01-2016 -15 (8-11-12)
05-01-2016 -5 (and so on...)
06-01-2016 -1
07-01-2016 -3
08-01-2016 12
09-01-2016 10
10-01-2016 28
当数据全部在一个表格中时，我无法做到这一点......
由于
答案 0 :(得分：2)
试试这个
SELECT t1.date Day,SUM(t2.Diff) FROM
amounts t1
INNER JOIN
(SELECT amounts.date Day, amounts.amount-prevamounts.amount Diff
FROM amounts inner join amounts prevamounts
ON amounts.date=date(prevamounts.date,'+1 years')) t2
ON t2.Day<=t1.date
group by t1.date;