计算在MySQL

Question

我使用的命令

select video_info count(distinct src_ip) from videoinfo 
    group by video_info 
    order by count(distinct src_ip) DESC 

来获取数据的2列，第一列表示每个视频项目，第二列记录他们有多少次被下载的标识符。

我也想计算一下，例如，5％的视频下载了两次，10％的视频下载了10次，然后将百分比数字和下载时间记录到两个数组中。

Mysql是否支持这种计算？或者我需要切换到Python来做到这一点？如果是这样，如何在Python中做到这一点？

Answer 1

在Python中你可以使用这个：

cur.execute("SELECT video_info, COUNT(distinct src_ip) " 
      "FROM videoinfo " 
      "GROUP BY video_info " 
      "ORDER BY COUNT(DISTINCT src_ip) DESC") 

counter = dict(cur) 
for n in xrange(1, max(counter.itervalues()) + 1): 
    perc = 100./sum(1 for nb in counter.itervalues() if nb == n)/len(counter) 
    if perc: 
     print '%.f%% videos have been downloaded %d times' % (perc, n) 

随着counter = {'a': 1, 'b': 1, 'c': 2, 'd': 1, 'e': 2, 'f': 3}这个打印：

50% videos have been downloaded 1 times 
33% videos have been downloaded 2 times 
17% videos have been downloaded 3 times