[thelist] MySQL query with two left joins

[Sarah]

I am currently working on a site which is basically a large repository of 
documents, sorted into a hierarchy of categories. So, each category can 
have multiple children, and each category has one parent. Each document can 
belong to multiple categories. Here are the important fields in the tables 
in question:

CATEGORIES
----------
CategoryID
ParentCategoryID
Title

DOCUMENTS
---------
DocumentID
Title

JN_DOCUMENTCATEGORIES
---------------------
DocumentID
CategoryID

In the admin system for the site, I am trying to output a list of child 
categories of one parent. I would like to include the count of the 
categories' documents and the count of the categories' sub-categories in 
this list as well, but I can't quite figure out how to make my left joins 
cooperate. Here is the query I am using:

    SELECT c.CategoryID,
           c.ParentCategoryID,
           c.Title,
           COUNT(cc.CategoryID) AS SubCatCount,
           COUNT(dc.DocumentID) AS DocCount
      FROM Categories c
LEFT JOIN Categories cc
        ON c.CategoryID = cc.ParentCategoryID
LEFT JOIN jn_DocumentCategories dc
        ON c.CategoryID = dc.CategoryID
     WHERE c.ParentCategoryID = 2
  GROUP BY c.CategoryID, c.ParentCategoryID, c.Title
  ORDER BY c.Title

When I run this query, any row that should have a number greater than 0 for 
SubCatCount and DocCount is returning the product of SubCatCount * DocCount 
in both columns. I hope my description of the problem makes sense! Any help 
in this would be appreciated.

TIA

Sarah