What can be used in a SQL query?

Question

PostgreSQL

Is it possible to get the names of tasks and the number of executions (label 'done'), as well as the number of rejections (label 'refused') using 1 request. So far, it has only been possible to display the names of the tasks and only the number of completions/rejections. It was not possible to display 3 parameters at the same time ...

spoiler

Answer 1

Easier

select _task, 
count(*) filter(where _status = 'done') as done_cnt,
count(*) filter(where _status = 'refused') as refused_cnt
from test
where _status in ('done', 'refused')
group by _task;