using group by in oracle not for count(*) but for min() function

Question

how to use group by for 3 columns it is showing an error that it is not a group by expression. here is the query.

select
   brewer.name as brewer,beer.name as beer,count(ratings.score) as LowestRating
from ratings,beer,brewer
where ratings.beer=beer.id and beer.brewer=brewer.id
group by brewer,beer; 

Answer 1

You should GROUP BY by columns, not whole tables:

select
     brewer.name as brewer,
     beer.name as beer,
     count(ratings.score) as LowestRating
  from
    ratings,
    beer,
    brewer
where
  ratings.beer = beer.id
  and beer.brewer = brewer.id
group by brewer.name, beer.name;