Question

我试图提取网站点击总数加上每个城市每天每个客户的变化率（增加/减少率），作为单个SQL查询中的百分比但不能正确。

我在

创建了一个示例

http://www.sqlfiddle.com/#!9/fd279/8

我可以请求协助吗？

Answer 1

尝试避免内连接，无论如何都有错误的条件（t1.hitDate = t2.hitDate and t1.hitDate-1 = t2.hitDate无法满足）：

select 
  t1.HitDate,
  t1.City,
  t1.Client,
  SUM(t1.NumVisits)  -   IFNULL((SELECT SUM(t2.NumVisits) FROM PAGE_HITS t2 WHERE t2.HitDate = t1.HitDate-1 AND t2.City = t1.City AND t2.Client = t1.Client), 0)  as rate_of_change
from
  PAGE_HITS t1
WHERE
t1.Client='C'
 group by
   HitDate,
   City
   ORDER BY HitDate;

Answer 2

获得基于百分比的增加/减少

select 
  t1.HitDate,
  t1.City,
  t1.Client,
    SUM(t1.NumVisits),
  IFNULL(((SUM(t1.NumVisits)  -   IFNULL((SELECT SUM(t2.NumVisits) FROM PAGE_HITS t2 WHERE t2.HitDate = t1.HitDate-1 AND t2.City = t1.City AND t2.Client = t1.Client), 0)) * 100) / IFNULL((SELECT SUM(t2.NumVisits) FROM PAGE_HITS t2 WHERE t2.HitDate = t1.HitDate-1 AND t2.City = t1.City AND t2.Client = t1.Client), 0),0)  as rate_of_change
from
  PAGE_HITS t1
WHERE
t1.Client='C'
 group by
   HitDate,
   City
   ORDER BY HitDate;

Answer 3

首先制作一个像rownum这样的唯一编号并进行相同的查询并加入rownum列然后你可以看到前一个月作为新列并计算变化率。

SELECT  A.HitDate, A.City, A.sumThis, B.sumFormer, (A.sumThis / B.sumFormer - 1) * 100 as 'ChangingRate'
From    (
        select @rownum1:=@rownum1 + 1 as 'rownum1', HitDate, City, sum(NumVisits) as 'sumThis'
        from page_hits, (Select @rownum1:=0) R
        Where client = 'C'
        Group by HitDate, City
        ) A
Left Join (
        select @rownum2:=@rownum2 + 1 as 'rownum2', HitDate, City, sum(NumVisits) as 'sumFormer'
        from page_hits, (Select @rownum2:=0) R
        Where client = 'C'
        Group by HitDate, City
        ) B On A.rownum1 - 1 = B.rownum2

MySQL - 总计数＆amp;单个SQL查询中的更改率

3 个答案: