Question

我试图通过在Amazon Redshift上使用以下查询找出retention rate：

    WITH t AS (
SELECT ga.ownerid,
       DATE_PART('month',ga.creationtime) AS month,
       COUNT(*) AS item_transactions,
       LAG(DATE_PART('month',ga.creationtime)) OVER (PARTITION BY ownerid ORDER BY DATE_PART('month',ga.creationtime)) = DATE_PART('month',ga.creationtime) -interval '1 month' OR NULL AS repeat_transaction
FROM flx2.groupactivities ga
  JOIN auth.members m ON ga.ownerid = m.id
WHERE ga.activitytype = 'assign'
AND   ga.groupid NOT IN (SELECT groupid
                         FROM (SELECT groupid,
                                      COUNT(DISTINCT memberid)
                               FROM flx2.grouphasmembers
                               GROUP BY groupid
                               HAVING COUNT(DISTINCT memberid) = 1))
AND   ga.ownerid IN (SELECT memberid FROM auth.memberhasroles WHERE roleid = 5)
AND   ga.ownerid NOT IN (SELECT memberid FROM auth.memberhasroles WHERE roleid = 25)
GROUP BY ga.ownerid,
         DATE_TRUNC('month',ga.creationtime)
ORDER BY ga.ownerid,
         DATE_TRUNC('month',ga.creationtime)
   )
SELECT month
      ,sum(item_transactions) AS num_trans
      ,count(*) AS num_buyers
      ,count(repeat_transaction) AS repeat_buyers
      ,round(
          CASE WHEN sum(item_transactions) > 0
             THEN count(repeat_transaction) / sum(item_transactions) * 100
             ELSE 0
          END, 2) AS buyer_retention
FROM   t
GROUP  BY 1
ORDER  BY 1;

但是它给了我以下错误：

An error occurred when executing the SQL command:
WITH t AS (
SELECT ga.ownerid,
       DATE_TRUNC('month',ga.creationtime) AS month,
       COUNT(*) AS item_transactions,
       LAG(DATE_TRUNC('month...

[Amazon](500310) Invalid operation: ORDER/GROUP BY expression not found in targetlist;

Execution time: 0.29s
1 statement failed.

我认为这里的LAG功能有问题，但我不太确定。我从帖子here收到了此查询，并根据我的要求对其进行了修改。

请有人帮我解决这里出了什么问题吗？

我提前感谢你的帮助。

Answer 1

快速查看，但lag本身不是汇总函数，因此repeat_transaction需要包含group by。

'LAG'功能在Amazon Redshift中不起作用

1 个答案: