Merhaba

SELECT COUNT( order_product.product_id ) AS toplamsatis, order_product.product_id, product.manufacturer_id
FROM order_product
INNER JOIN product ON product.product_id = order_product.product_id
GROUP BY order_product.product_id
ORDER BY toplamsatis DESC

result
-----------
toplamsatis product_id manufacturer_id
153 127 39
115 293 53
100 168 39
93 241 49
76 416 30
72 124 37
69 154 41
62 132 39
57 57 27
53 297 54


şeklinde

Ancak manufacturer_id baz alarak tekrarlanan kayıt istemiyorum, ki böylece opencartta en çok satış yapan markaları sıralamak istiyorum.