MySQL query GROUPing from one table, excluding results found in another sub query

Question

Let's say I have two tables - ADDONS and DOWNLOADS.

ADDONS dictates which apps come with which addons for FREE.
DOWNLOADS logs addon downloads from all apps, those that include for free and not.

ADDONS  
appname  | varchar  
appaddon | varchar

DOWNLOADS  
id       | int  
appaddon | varchar  
appname  | varchar  
source   | varchar  
date     | datetime  

I am trying to write a query that shows the count of each appaddon in DOWNLOADS where it was NOT included for free in ADDONS.

I got as far as: "SELECT appaddon, count(id) FROM downloads GROUP BY appaddon ORDER BY count(id) DESC" - but that is inclusive of apps that included it for free and those that do not.

Can anyone point me in the right direction on this?

---

Update:

Example: Imagine I have two holiday themed apps - one for Christmas, one for Halloween, and each app allows you to download costumes that are included with the app (for example Halloween lets you download a witch, skeleton or jack o lantern, and Christmas lets you download a Santa or elf). BUT if someone upgrades from within the app, they can download ANY of the available costumes (so Christmas upgraded could download a skeleton, or Halloween upgraded could download an Elf).

I am trying to get a count of the downloads that are NOT included without upgrading. So I want to exclude the witches downloaded by Halloween, and the Santas downloaded by Christmas, but get a count of the witches, skeletons, elves, etc downloaded by the OTHER apps.

Here is some example data:

ADDONS  
appname     | appaddon  
========================  
halloween   | jackolantern  
halloween   | skeleton  
halloween   | witch  
christmas   | santa  
christmas   | elf  
christmas   | reindeer  
easter      | bunny  
allholidays | bunny

DOWNLOADS  
id | appaddon  | appname   | date  
=======================================
1  | skeleton  | halloween | 2012-10-15  
2  | skeleton  | halloween | 2012-10-15  
3  | witch     | halloween | 2012-10-16  
4  | santa     | christmas | 2012-10-16  
5  | elf       | christmas | 2012-10-16  
6  | witch     | christmas | 2012-10-16  
7  | bunny     | christmas | 2012-10-16  
8  | bunny     | halloween | 2012-10-17  
9  | bunny     | easter    | 2012-10-18

Based on above, I would expect the results:

appaddon  | count
=================
bunny     | 2
witch     | 1

Answer 1

I think I figured it out! Required me to use WHERE NOT EXISTS.

SELECT appaddon, count(id) FROM DOWNLOADS
WHERE NOT EXISTS (
  SELECT appaddon FROM ADDONS
  WHERE DOWNLOADS.appname = ADDONS.appname
  AND DOWNLOADS.appaddon = ADDONS.appaddon)
GROUP BY appaddon

Fiddler for it here

Answer 2

 SELECT appaddon, count(id) FROM downloads 
    left join addons on addons.appname=downloads.appname
    where addons.appname is null
    GROUP BY downloads.appaddon ORDER BY count(id) DESC

Answer 3

This might work for you:

SELECT DOWNLOADS.appaddon, COUNT(*) FROM DOWNLOADS
    INNER JOIN ADDONS ON (DOWNLOADS.appaddon = ADDONS.appaddon)
    WHERE DOWNLOADS.appname != ADDONS.appname
    GROUP BY DOWNLOADS.appaddon;

Here is the SQL Fiddle for it: link