sql - SQL-计算计数百分比(列)

Question

我有以下一段代码，它计算事件列中出现的次数。

SELECT event, count(event) as event_count   
FROM event_information
group by event

event   event_count
a       34
b       256
c       45
d       117
e       3

我希望能够像这样计算每一行的百分比。

event   event_count event_percent
a       34          7.47
b       256         56.26
c       45          9.89
d       117         25.71
e       3           0.66

Answer 1

SELECT event, 
       count(event) as event_count,
       count(event) * 100.0 / (select count(*) from event_information) as event_percent
FROM event_information
group by event