An Error Was Encountered

Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') AND (category_id = )' at line 1

SELECT product.product_id, product.product_name, product.product_description, product.product_image, product.product_price, product.product_url_alias FROM product, subcategory, category WHERE (product.fk_subcategory_id = subcategory.subcategory_id) AND (subcategory_id = ) AND (category_id = )