MYSQL count of count?

Question

I have a mysql table like:

id, visitorid, pageid

When a visitor hits the website it stores their visitor id and the page id as a row.

Answer 1

You can wrap your query inside another one:

SELECT
    cnt      AS page_visits
  , COUNT(*) AS number_of_visitors
FROM
    ( SELECT 
          COUNT(*) AS cnt                --- use: COUNT(DISTINCT page_id)
                                         --- for a different count
      FROM vislog 
      GROUP BY visid
   ) AS grp
GROUP BY cnt 
ORDER BY number_of_visitors ;

or (I suppose this makes more sense for passing the numbers to a chart), remove the ORDER BY which is the same as putting:

ORDER BY cnt ;