Question

SELECT      totalAmount
FROM        tbl
BETWEEN     'date1' AND 'date2'

GROUP BY    DATE(date created) 
ORDER BY    DATE(date created)

这给了我表中每天的总金额。但我想要的是与前一个条目（不一定是前一天）相比的增量值

表格可能类似于：

totalAmount    |    date created
---------------------------------
1000           |    1st Jan
1001           |    2nd Jan
1003           |    3rd Jan
1008           |    15th Jan

所以我的查询会返回： 1000,1001,1003,1008。

我真正想要的是：（与之前的条目相比较的数字 - 但不在BETWEEN日期范围内，以便开始我的实施），1,2,5

Answer 1

这要做到这一点：

SELECT IFNULL((t1.totalamount - t2.totalamount),0) as diff, t1.date_created
FROM view t1 LEFT OUTER JOIN view t2 
 ON t2.date = (SELECT MAX(date) FROM view WHERE date < t1.date)
WHERE t1.date_created BETWEEN 'date1' AND 'date2'
ORDER BY date_created

此查询的“查看”位置：

SELECT date_created, SUM(totalamount) FROM tbl GROUP BY date_created

Answer 2

试试这个：

SELECT      totalAmount
FROM        tbl
BETWEEN     'date1' AND 'date2'

GROUP BY    DATE(date created) 
ORDER BY    totalAmount DESC, DATE(date created)

Answer 3

您需要加入两个相同排名的子查询。我没有MySQL数据库来测试这个，但表单类似于：

select t1.TotalAmount, t1.DateCreated, 
    t1.TotalAmount - t2.TotalAmount as 'Delta'
from
(select rownum, TotalAmount
 from tbl
 order by DateCreated) t1
left outer join
(select rownum, TotalAmount
 from tbl
 order by DateCreated) t2
 on t1.rownum = t2.rownum + 1
 order by t1.rownum

从tbl'value1'中选择减去'previous value'

3 个答案: