MySQL statement combining a join and a count?

Question

I\'ve got a table of \'folders\'. I want to return all the records with the userId of 16.

SELECT * FROM `folders` WHERE userId = 16;

I\'ve

Answer 1

Do a sub query that groups by the Folders to get the count per folder, then join it to the first query like this:

    select
       f.*
       fc.Files
    from
       Folders f
--
       -- Join the sub query with the counts by folder     
       JOIN (select
               Folder,
               count(*) Files
             from
                files
             group by
                Folder ) as fc
          on ( fc.Folder = f.Folder )
    where
       f.userid = 16