Question

我随便使用phpMyAdmin建立了一个网站，并创建了以下SQL代码以获取前10天的最频繁价格，并将其与当前价格进行比较以确定价格下降。但是，我遇到的问题是，由于产品和价格的数量，它需要大约10秒钟才能运行。我正在寻找改善查询以减少网页加载时间的方法。

我有三个表产品，product_categories，价格。 product_categories是我要过滤的数据。表结构如下，但是不包括一些不相关的列：

价格表：

sku |产品价格| price_date |零售商

product_category表：

product_type | category_1 | category_2 | category_3

产品表：

product_type | sku |零售商|产品名称

Execution Plan

SELECT currentPrice as 'prodprice', meanPrice, priceDiff, prodDetails.sku, prodDetails.product_name, prodDetails.img FROM (
      SELECT products.sku, products.product_name, products.img, products.product_type, products.retailer, category_1, category_2, category_3 FROM products INNER JOIN product_categories on product_categories.product_type = products.product_type
      WHERE category_3 = 'Laptops') as prodDetails INNER JOIN (
      SELECT prices.product_price as 'currentPrice', prices.sku, prices.retailer, meanPrice, (prices.product_price/meanPrice)-1 as 'priceDiff' FROM prices RIGHT JOIN(
      SELECT MaxCountSub.sku, CountSub.product_price as 'meanPrice', CountSub.retailer
      FROM (SELECT prices.sku, prices.product_price, retailer, Count(prices.product_price) AS CountOfValue
            FROM prices
            WHERE price_date > CURRENT_DATE-10
            GROUP BY prices.sku, prices.product_price) As CountSub
            INNER JOIN 
          (SELECT dT.sku, Max(CountOfValue) As MaxCountOfValue, dT.retailer
            FROM
                (SELECT prices.sku, prices.product_price, retailer, Count(prices.product_price) AS CountOfValue
                  FROM prices WHERE price_date > CURRENT_DATE-10 GROUP BY prices.sku, prices.product_price) As dT
                  GROUP BY dT.sku) As MaxCountSub
            ON CountSub.sku = MaxCountSub.sku 
            AND CountSub.CountOfValue = MaxCountSub.MaxCountOfValue
            AND MaxCountSub.retailer = CountSub.retailer) as b 
      on b.retailer = prices.retailer and b.sku = prices.sku
      WHERE prices.price_date = CURRENT_DATE ORDER BY priceDiff ASC ) c on c.retailer = prodDetails.retailer and c.sku = prodDetails.sku  
      ORDER BY `c`.`priceDiff`  ASC LIMIT 8

产品表

+----------------+--------+----------+---------------+
|  product_type  |  sku   | retailer | product_name  |
+----------------+--------+----------+---------------+
| 2 in 1         | 475750 | J        | Dell Inspiron |
| 2 in 1 Devices | 324155 | H        | Lenovo Chrome |
| 2 in 1 Devices | 311148 | H        | HP Pavilion x |
| 2 in 1 Devices | 332274 | H        | HP Envy x360  |
| 2 in 1 Devices | 332261 | H        | Lenovo Ideapa |
| 2 in 1 Devices | 312084 | H        | HP Spectre x3 |
| Laptop         | 473661 | J        | Lenovo IdeaPa |
| Laptop         | 482998 | J        | Asus VivoBook |
| Laptops        | 331133 | H        | Acer Nitro 5  |
| Laptops        | 336095 | H        | Lenovo Ideapa |
| Laptops        | 326802 | H        | Predator Heli |
| Laptops        | 326712 | H        | Acer Nitro 5  |
| Laptops        | 326601 | H        | Acer Nitro 5  |
| Laptops        | 326589 | H        | Predator Trit |
| Laptops        | 336100 | H        | Lenovo Legion |
| Laptops        | 336101 | H        | Lenovo Legion |
| Laptops        | 311527 | H        | Acer Swift 5  |
| Laptops        | 295323 | H        | HP 14-inch Ce |
| Laptops        | 332257 | H        | Lenovo Ideapa |
| Laptops        | 327328 | H        | Acer Aspire 5 |
+----------------+--------+----------+---------------+

价格表

+--------+---------------+------------+----------+
|  sku   | product_price | price_date | retailer |
+--------+---------------+------------+----------+
| 295323 |           358 | 20/09/2020 | H        |
| 295323 |           358 | 21/09/2020 | H        |
| 295323 |           448 | 22/09/2020 | H        |
| 311148 |          1088 | 20/09/2020 | H        |
| 311148 |          1088 | 21/09/2020 | H        |
| 311148 |          1399 | 22/09/2020 | H        |
| 311527 |          1099 | 20/09/2020 | H        |
| 311527 |          1099 | 21/09/2020 | H        |
| 311527 |          1799 | 22/09/2020 | H        |
| 312084 |          1688 | 20/09/2020 | H        |
| 312084 |          1688 | 21/09/2020 | H        |
| 312084 |          1999 | 22/09/2020 | H        |
| 326712 |          1899 | 20/09/2020 | H        |
| 326712 |          1899 | 21/09/2020 | H        |
| 326712 |          2399 | 22/09/2020 | H        |
| 327328 |          1098 | 20/09/2020 | H        |
| 327328 |          1098 | 21/09/2020 | H        |
| 327328 |          1399 | 22/09/2020 | H        |
| 332261 |           999 | 20/09/2020 | H        |
| 332261 |           999 | 21/09/2020 | H        |
| 332261 |          1199 | 22/09/2020 | H        |
| 332274 |          1799 | 20/09/2020 | H        |
| 332274 |          1799 | 21/09/2020 | H        |
| 332274 |          2199 | 22/09/2020 | H        |
| 336095 |          1349 | 20/09/2020 | H        |
| 336095 |          1349 | 21/09/2020 | H        |
| 336095 |          1799 | 22/09/2020 | H        |
| 482998 |         763.3 | 20/09/2020 | J        |
| 482998 |         763.3 | 21/09/2020 | J        |
| 482998 |         763.3 | 22/09/2020 | J        |
+--------+---------------+------------+----------+

产品类别表

+----------------+-------------+------------+------------+
|  product_type  | category_1  | category_2 | category_3 |
+----------------+-------------+------------+------------+
| 2 in 1         | Electronics | Computers  | Laptops    |
| 2 in 1 Devices | Electronics | Computers  | Laptops    |
| Chromebook     | Electronics | Computers  | Laptops    |
| Laptop         | Electronics | Computers  | Laptops    |
| Laptops        | Electronics | Computers  | Laptops    |
| MacBook Air    | Electronics | Computers  | Laptops    |
| MacBook Pro    | Electronics | Computers  | Laptops    |
| Netbook        | Electronics | Computers  | Laptops    |
| Ultrabook      | Electronics | Computers  | Laptops    |
| 2 in 1 Laptops | Electronics | Computers  | Laptops    |
+----------------+-------------+------------+------------+

前10天的MySQL通用价格与当前价格的比较-MySQL性能改进

0 个答案: