How to Find the Percentage of A column-CodePudding

I Have column which has a value for each day for example :

Event Day  Category
10-10-10      1
10-10-10      2
11-10-10      1
11-10-10      2
11-10-10      2
11-10-10      2

I want to do percentage for each Category for each day.

So output :

Event Day  Category   %
10-10-10      1      50
10-10-10      2      50
11-10-10      1      25
11-10-10      2      75

My Query :

Select event_day, Category, count(*) from my_table group by event_day, Category;

How to get the total count for a Day so I can derived the percentage.

CodePudding user response：

in mysql 8 :

Select event_day
       , Category
       , count(*)* 100.0 /sum(count(*)) over (partition by event_day)
from my_table 
group by event_day, Category;