39.Shopper - 购买促销活动产品

dimestore商城了一款今日爆款，有家电销售低于6.99美元吗?

SELECT product.name, product.unitPrice, product.categories 
FROM product UNNEST product.categories AS categories 
WHERE categories = "Appliances" AND product.unitPrice < 6.99

结果：

{
  "results": [
    {
      "categories": [
        "Appliances"
      ],
      "name": "Ball Cap Buddy",
      "unitPrice": 5.61
    }
  ]
}