Unknown column error in this COUNT MySQL statement?

Question

Error is

Unknown column \'num\' in \'where\' clause

SELECT COUNT(*) AS num, books_bookid
FROM bookgenre_has_books
WHERE         


        

Answer 1

We can write like this

    SELECT COUNT(*) , books_bookid
   FROM bookgenre_has_books
   GROUP BY books_bookid
   having count(*) > 10

you are checking for duplicates more then for that column books_bookid