Best sellers "page"

[numinix]

I'm working on a simple module that loads the best sellers from a given category from the previous x months. Here is the SQL query:

SELECT  DISTINCT (p2c.products_id), SUM( op.products_quantity )  AS products_ordered, pd.products_name, p.products_image
FROM products_to_categories  p2c
LEFT  JOIN orders_products op ON ( op.products_id = p2c.products_id ) 
LEFT  JOIN orders o ON ( o.orders_id =  op.orders_id ) 
LEFT  JOIN products_description  pd ON ( pd.products_id = p2c.products_id ) 
LEFT  JOIN products p ON ( p.products_id =  p2c.products_id ) 
WHERE p.products_status =1
AND pd.language_id =   '1'
AND (o.date_purchased >=  '2010-03-12'
AND o.date_purchased <=  '2010-05-13')
AND p2c.categories_id
IN ( 8, 6, 10, 11, 12, 4, 7, 9, 13, 5  ) 
GROUP  BY p2c.products_id
ORDER  BY products_ordered DESC , products_name ASC; 

The issue I am having is that if a product is linked, it doubles up the products_ordered. Any fresh eyes see the mistake?

If anyone was wondering how to do this, the following query worked:

SELECT  DISTINCT (p2c.products_id), SUM( op.products_quantity )  AS products_ordered, pd.products_name, p.products_image
FROM products_to_categories  p2c
LEFT  JOIN orders_products op ON ( op.products_id = p2c.products_id ) 
LEFT  JOIN orders o ON ( o.orders_id =  op.orders_id ) 
LEFT  JOIN products_description  pd ON ( pd.products_id = p2c.products_id ) 
LEFT  JOIN products p ON ( p.products_id =  p2c.products_id ) 
WHERE p.products_status =1
AND pd.language_id =   '1'
AND (o.date_purchased >=  '2010-03-12'
AND o.date_purchased <=  '2010-05-13')
AND p2c.categories_id
IN ( 8, 6, 10, 11, 12, 4, 7, 9, 13, 5  ) 
GROUP  BY p2c.products_id, p2c.categories_id
ORDER  BY products_ordered DESC , products_name ASC;