Question

我对SQL很陌生并且一直试图解决这个问题..但仍然没有运气。如果有人在这里可以帮助我，我将不胜感激。

我有一个包含列的数据库： ClientID， VisitID， Date， PurchaseID（数组）等

我想要达到的目标是： ClientID， Last Visit Date， First Visit Date， Last Purchase Date， Visits Count， Purchases Count， Visits After Last Purchase Count

最后购买次数后的访问次数 - 我坚持了。

SELECT 
ClientID, 
FirstVisit, 
LastVisit, 
LastPurchaseDate, 
Visits, 
Purchases, 
VisitsAfterPurchase
FROM 
(
SELECT 
    h.ClientID, 
    max(h.Date) AS LastVisit, 
    min(h.Date) AS FirstVisit, 
    count(VisitID) AS Visits
FROM s7_visits AS h 
WHERE Date > '2017-12-01'
GROUP BY h.ClientID
LIMIT 100
) 
ANY LEFT JOIN 
(
SELECT 
    d.ClientID, 
    max(d.Date) AS LastPurchaseDate, 
    sum(length(d.PurchaseID)) AS Purchases, 
    sum(
    (
        SELECT count(x.VisitID)
        FROM s7_visits AS x 
        WHERE x.ClientID = d.ClientID
        HAVING x.Date >= max(d.Date)
    )) AS VisitsAfterPurchase
FROM s7_visits AS d 
WHERE (length(PurchaseID) > 0) AND (Date > '2017-12-01')
GROUP BY d.ClientID
) USING (ClientID)

我使用的数据库是Yandex Clickhouse。 USING事情绝对正常（使用它代替ON）

此查询给出了错误：

DB ::异常：列日期不在聚合函数下，不在GROUP BY ..

示例数据：

  +----------+---------+------------+------------+
  | CliendID | VisitID |    Date    | PurchaseID |
  +----------+---------+------------+------------+
  |      123 |     136 | 01.12.2017 |            |
  |      123 |     522 | 05.12.2017 |            |
  |      123 |     883 | 08.12.2017 |            |
  |      123 |     293 | 09.12.2017 | ['345']    |
  |      123 |     278 | 12.12.2017 |            |
  |      123 |     508 | 12.12.2017 |            |
  |      123 |     562 | 15.12.2017 |            |
  |      123 |     523 | 21.12.2017 |            |
  |      456 |     736 | 29.11.2017 |            |
  |      456 |     417 | 03.12.2017 |            |
  |      456 |     950 | 04.12.2017 |            |
  |      456 |     532 | 05.12.2017 | ['346']    |
  |      456 |     880 | 09.12.2017 |            |
  |      456 |     296 | 12.12.2017 |            |
  |      456 |     614 | 15.12.2017 |            |
  +----------+---------+------------+------------+

结果将是：

  +----------+-----------------+------------------+--------------------+--------------+-----------------+----------------------------------+
  | ClientID | Last Visit Date | First Visit Date | Last Purchase Date | Visits Count | Purchases Count | Visits After Last Purchase Count |
  +----------+-----------------+------------------+--------------------+--------------+-----------------+----------------------------------+
  |      123 |      21.12.2017 |       01.12.2017 |         09.12.2017 |            8 |               1 |                                4 |
  |      456 |      15.12.2017 |       29.11.2017 |         05.12.2017 |            7 |               1 |                                3 |
  +----------+-----------------+------------------+--------------------+--------------+-----------------+----------------------------------+

Answer 1

问题归因于HAVING x.Date >= MAX(d.Date)。引用x.Date列是没有意义的，因为您首先会聚合x.ClientID = d.ClientID的所有行，而x.Date只会来自该组中随机选择的行。

如果要选择要计算的行，则需要在WHERE子句中执行此操作。所以子查询应该是：

(
SELECT 
    d.ClientID, 
    max(d.Date) AS LastPurchaseDate, 
    sum(length(d.PurchaseID)) AS Purchases, 
    sum(
    (
        SELECT count(x.VisitID)
        FROM s7_visits AS x 
        WHERE x.ClientID = d.ClientID AND x.Date >= max(d.Date)
    )) AS VisitsAfterPurchase
FROM s7_visits AS d 
WHERE (length(PurchaseID) > 0) AND (Date > '2017-12-01')
GROUP BY d.ClientID
) USING (ClientID)

相关子查询。在最后购买日期之后计算访问次数

1 个答案: