SQL / PHP：显示数据库中销售量最高的3种产品

试试这个：

$sql = "SELECt SUM(order_count.number) AS total, image.image_link AS image_link FROM product JOIN order_count ON product.product_id = order_count.product_id JOIN image ON product.image_id = image.image_idGROUP BY order_count.product_id ORDER BY total DESC LIMIT 3";