distinct count in mysql group by

Question

I am trying to find the unique count of the domains using apps.

The below query does not fetch any results. However if run the same query without distinct it returns the counts

SELECT 
  apps, category, COUNT(distinct(domain)) as counts
FROM table1.techs
GROUP BY apps

Answer 1

distinct is not a function, so the brackets serve no purpose:

SELECT 
    apps, category, COUNT(distinct domain) as counts
FROM table1.techs
GROUP BY apps, category

Also, more importantly, you must list all non-aggregated columns in the GROUP BY clause to get meaningful results, OR remove category entirely from query.