Запрос на выборку товаров с метками - Общие вопросы и ошибки

$query = "SELECT
	`name_ru-RU` AS product_name ,
	`label_id` AS label_id ,
	`product_price` AS product_price ,
	`product_thumb_image` AS product_thumb_image
	FROM `#__jshopping_products` AS prod
	LEFT JOIN `#__jshopping_product_labels` AS label ON label.id = prod.label_id
	LEFT JOIN `#__jshopping_products_to_categories` AS pr_cat ON pr_cat.`product_id` = prod.`product_id` WHERE pr_cat.category_id = $this->category_id AND `product_price` !=0 AND ORDER BY RAND() LIMIT 3";