два запроса выдают ошибку:
Error in query (1055): Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'test.authors.name' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
Что делать?
Вот запросы:
select authors.name, count(books.id) as cnt
from books, authors
group by books.author_id
having count(books.id) = 0
select authors.name, count(books.id) as cnt
from books, authors
group by books.author_id
having count(books.id) > 1
Средний
