Question

想要确定运行SQL teradata查询的方法，我可以通过cust_id，acct_num获得构成客户设备计数的最高组合，然后是每个组合总数的平均千瓦数。

所以客户可以拥有1台设备，我需要列出设备和平均千瓦，然后我想要下一个最高的客户设备组合，并需要列出“内部”和“车库”的组合然后获取该组合总数的平均字节数。

源数据样本：

Electric_device Total_Kilowatts CUST_ID ACCT_NUM    DEVICE_TYPE
2                            75         11556632    1   In House
1                            60         11556632    1   In garage
5                            25         11556632    2   Outside
6                          1155         11556632    2   GPS

结果集将超过100万客户，如下所示：

Count_of_Cust_id    Combinations    Average_Kilowatts
         800,000    In House                      75
         100,000    In House, In Garage           68

Answer 1

以下查询按步骤计算各种值：

1对于Cust_ID和Acct_Num

的每个组合，连接设备类型

2总计_Kilowatts总结为Cust_ID和Acct_Num的每个组合

3数据按Device_Type组合分组，并获得Cust_ID和Average_Kilowatts的计数。

WITH RECURSIVE device_types (cust_id, acct_num, devices, lvl)
   AS
   (
    SELECT cust_id, acct_num, MIN(device_type), 1
    FROM customers
    GROUP BY cust_id, acct_num, 1
    UNION ALL
    SELECT cust_id, acct_num, TRIM(device_type) || ', ' || devices, lvl+1
    FROM customers c INNER JOIN device_types dt
    ON c.cust_id = dt.cust_id AND c.acct_num = dt.acct_num AND device_type > devices
   ),
grouped_devices AS  
  (
   SELECT cust_id, acct_num, devices
   FROM device_types
   QUALIFY RANK() OVER(PARTITION BY cust_id, acct_num ORDER BY lvl DESC) = 1; 
 ),
summed_kilowatts AS
 (
  SELECT cust_id acct_num, sum(total_kilowatts) total_kilowatts
  FROM customers
  GROUP BY cust_id acct_num
 )
SELECT gd.devices Combinations, COUNT(DISTINCT gd.cust_id) Count_of_Cust_id, SUM(sk.total_kilowatts)/COUNT(DISTINCT gd.cust_id) Average_Kilowatts
FROM grouped_devices gd
INNER JOIN summed_kilowatts sk ON gd.cust_id = sk.cust_id AND gd.acct_num = sk.acct_num
GROUP BY gd.devices
ORDER BY gd.devices;

<强>参考：

Concat rows as a single column in Teradata on The Simple Programmer blog

将多个字段编译为一个

1 个答案: