意外的行数。加入不当?

时间:2018-02-21 20:03:12

标签: sql impala

我很难过这个。我是初学者,也许我已经深入了解联盟。作为一种方法,我分别为结果的不同功能编写了查询。我现在正在尝试合并,它正在破碎。

我使用Impala查询并在使用HIVE导入HDFS之前在MySQL中创建表。

有效的查询是:

SELECT carrier, zone, speed, min_price, price
FROM (SELECT carrier, total_wt, zone, speed, price, MIN(price) OVER(PARTITION BY speed) as min_price
      FROM shipping_prices
      WHERE total_wt IN (
    SELECT
        SUM(prod.shipping_wt)
        FROM order_details ordet
        JOIN products prod
        ON prod.prod_id = ordet.prod_id
        WHERE ordet.order_id = 5841506
        GROUP BY ordet.order_id)
    AND zone IN (
    SELECT cal_zone
      FROM (
        SELECT carrier, dest_zip, origin_zip, zone, MIN(zone) OVER(PARTITION BY carrier) as cal_zone
          FROM shipping_zones
            WHERE (origin_zip = 402 OR origin_zip = 950) AND dest_zip = '560'
          ) t
    WHERE zone=cal_zone)
      ) z
WHERE price=min_price
ORDER BY speed DESC;

返回:

+---------+------+-------+-----------+-------+
| carrier | zone | speed | min_price | price |
+---------+------+-------+-----------+-------+
| fedex   | 4    | slow  | 10.86     | 10.86 |
| usps    | 4    | med   | 11.15     | 11.15 |
| usps    | 4    | fast  | 40.55     | 40.55 |
+---------+------+-------+-----------+-------+

我遇到问题的查询似乎在最后结果之前的步骤失败了,当它应该找到9个价格总计,每个级别每个运营商一个。相反,它返回27,因此每个级别每个运营商找到9个价格。这没有意义,因为每个级别每个运营商只有3个价格。这是查询:

SELECT lev5.zone, lev5.cust_id, lev5.total_wt, lev5.zip_shrt, lev5.order_id, lev5.carrier, pric.speed, pric.price, MIN(price) OVER(PARTITION BY speed) as min_price
FROM (
      SELECT lev4.cust_id, lev4.total_wt, lev4.zip_shrt, lev4.order_id, lev4.carrier, lev4.zone
      FROM (
             SELECT lev3.cust_id, lev3.total_wt, lev3.zip_shrt, lev3.order_id, zon.carrier, zon.origin_zip, zon.dest_zip, zon.zone, MIN(zon.zone) OVER(PARTITION BY zon.carrier) as calc_zone
             FROM (
                    SELECT lev2.cust_id, SUM(shipping_wt)/2 AS total_wt, STRLEFT(lev2.zipcode, 3) AS zip_shrt, lev2.order_id
                    FROM (
                           SELECT lev1.zipcode, lev1.cust_id, lev1.order_id, ordet.prod_id
                       FROM (
                          SELECT cus.zipcode, cus.cust_id, ord.order_id
                          FROM orders ord
                          JOIN customers cus ON ord.cust_id = cus.cust_id
                          WHERE ord.order_id = 5841506 
                            ) lev1
                       JOIN order_details ordet
                       ON lev1.order_id = ordet.order_id
                       WHERE ordet.order_id = lev1.order_id
                         ) lev2
                    JOIN products prod
                    ON lev2.prod_id = prod.prod_id
                    GROUP BY lev2.cust_id, zip_shrt, lev2.order_id
                  ) lev3
             JOIN shipping_zones zon
             ON lev3.zip_shrt = zon.dest_zip
             WHERE (origin_zip = 402 OR origin_zip = 950) AND dest_zip = lev3.zip_shrt
           ) lev4
      WHERE lev4.zone = calc_zone
     ) lev5
JOIN shipping_prices pric
ON lev5.zone = pric.zone AND lev5.total_wt = pric.total_wt;

返回:

+------+---------+----------+----------+----------+---------+-------+-------------------+-----------+
| zone | cust_id | total_wt | zip_shrt | order_id | carrier | speed | price             | min_price |
+------+---------+----------+----------+----------+---------+-------+-------------------+-----------+
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | med   | 22.24             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | med   | 23.57             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | med   | 11.15             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | med   | 11.15             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | med   | 22.24             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | med   | 23.57             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | med   | 23.57             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | med   | 11.15             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | med   | 22.24             | 11.15     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | slow  | 10.86             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | slow  | 10.86             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | slow  | 11.15             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | slow  | 10.86             | 10.86     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | fast  | 69.93000000000001 | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | fast  | 40.55             | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | ups     | fast  | 65.94             | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | fast  | 69.93000000000001 | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | fast  | 40.55             | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | usps    | fast  | 65.94             | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | fast  | 69.93000000000001 | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | fast  | 40.55             | 40.55     |
| 4    | 1050349 | 4        | 560      | 5841506  | fedex   | fast  | 65.94             | 40.55     |
+------+---------+----------+----------+----------+---------+-------+-------------------+-----------+

我进入excel确认(shipping_prices的源数据)并执行了COUNTIFS函数,它只返回了9行。

我真的很感激一些帮助。我自己一直试图解决这个问题,但也许是因为我缺乏连接知识或其他我没有经验的东西。我为自己感到非常自豪,我已经到了这一点,但这个障碍正在扼杀我。

谢谢

1 个答案:

答案 0 :(得分:0)

这就是我最终得到的结果:

SELECT lev6.order_id, lev6.carrier, lev6.speed, lev6.min_price AS cheapest_price
FROM (
SELECT lev5.zone, lev5.cust_id, lev5.total_wt, lev5.zip_shrt, lev5.order_id, lev5.origin_zip, lev5.carrier, pric.speed, pric.price, MIN(pric.price) OVER(PARTITION BY speed) as min_price
FROM (
      SELECT lev4.cust_id, lev4.total_wt, lev4.zip_shrt, lev4.order_id, lev4.carrier, lev4.zone, lev4.origin_zip
      FROM (
             SELECT lev3.cust_id, lev3.total_wt, lev3.zip_shrt, lev3.order_id, zon.carrier, zon.origin_zip, zon.dest_zip, zon.zone, MIN(zon.zone) OVER(PARTITION BY zon.carrier) as calc_zone
             FROM (
                    SELECT lev2.cust_id, SUM(shipping_wt)/2 AS total_wt, STRLEFT(lev2.zipcode, 3) AS zip_shrt, lev2.order_id
                    FROM (
                           SELECT lev1.zipcode, lev1.cust_id, lev1.order_id, ordet.prod_id
                       FROM (
                          SELECT cus.zipcode, cus.cust_id, ord.order_id
                          FROM orders ord
                          JOIN customers cus ON ord.cust_id = cus.cust_id
                          WHERE ord.order_id = 6453746
                            ) lev1
                       JOIN order_details ordet
                       ON lev1.order_id = ordet.order_id
                       WHERE ordet.order_id = lev1.order_id
                         ) lev2
                    JOIN products prod
                    ON lev2.prod_id = prod.prod_id
                    GROUP BY lev2.cust_id, zip_shrt, lev2.order_id
                  ) lev3
             JOIN shipping_zones zon
             ON lev3.zip_shrt = zon.dest_zip
             WHERE (origin_zip = 402 OR origin_zip = 950) AND dest_zip = lev3.zip_shrt
           ) lev4
      WHERE lev4.zone = calc_zone
     ) lev5
JOIN shipping_prices pric
ON lev5.zone = pric.zone AND lev5.total_wt = pric.total_wt
WHERE lev5.carrier = pric.carrier
) lev6
WHERE lev6.price = lev6.min_price
ORDER BY lev6.speed DESC;

我的问题是我的lev5上没有WHERE条件。我补充说:

WHERE lev5.carrier = pric.carrier

这消除了重复,并正确地返回了9个运费,每个运营商3个(慢,中,快)。然后我添加lev6只返回每个速度的最低价格。

@Thorsten Kettner至于为什么我必须将产品重量的总和除以2,遗憾的是我没有答案。如果我没有,它会返回订单实际重量的两倍,不知道为什么。

这个查询不是防弹,也没有针对空值和所有情况进行测试(比如当两个价格在相同的速度下相等时),但它足以满足我想做的事情,并证明了概念。