sql - Teradata 中的 "First order by"

Question

我在将 SQL 语句从 Oracle 转换为 Teradata 时遇到问题。 Oracle中的说法是:

SELECT ar.account_no,
MAX (ah.bal_acct) KEEP (DENSE_RANK FIRST ORDER BY ah.created_t desc) 
FROM ar
   JOIN ah ON ah.obj_id0 = ar.poid_Id0
   JOIN acc ON a.poid_id0 = ar.account_obj_Id0
WHERE acc.account_no = '1234'
AND ah.created_t <= 1434753495
GROUP BY ar.account_no

我需要在 Teradata 中执行类似的语句。我尝试了一些东西

QUALIFY ROW_NUMBER() OVER( PARTITION BY max(ah.bal_acct) ORDER BY ah.created_t desc) = 1

但我总是遇到错误:选定的非聚合值必须是关联组的一部分。

这就是我得到的:

Select ar.account_no, ah.created_t, ah.bal_acct
FROM VD_REPLICA_BRM.pi_tp_acct_ar_t ar
    JOIN VD_REPLICA_BRM.pi_tp_acct_ar_hist_T ah ON ah.obj_id0 = ar.poid_Id0
    JOIN VD_REPLICA_BRM.pi_account_t acc ON acc.poid_id0 = ar.account_obj_Id0
WHERE acc.account_no = '00003095660515'
    AND ah.created_t <= CAST('2016-10-31' AS DATE FORMAT 'YYYY-MM-DD')
QUALIFY ROW_NUMBER() OVER( PARTITION BY max(ah.bal_acct) ORDER BY ah.created_t desc) = 1
GROUP BY ar.account_no

我哪里做错了？

Answer 1

我不确定您是否可以使用 qualify 来做到这一点。等效的语句是:

SELECT ar.account_no, ah.created_t, ah.bal_acct
FROM (SELECT ar.account_no, ah.created_t, ah.bal_acct,
             ROW_NUMBER() OVER (PARTITION BY ar.account_no ORDER BY ah.created_t DESC) as seqnum
      FROM ar JOIN
           ah
           ON ah.obj_id0 = ar.poid_Id0 JOIN
           acc
           ON a.poid_id0 = ar.account_obj_Id0
      WHERE acc.account_no = '1234' AND ah.created_t <= 1434753495
     ) t
WHERE seqnum = 1;

呃。您可以使用QUALIFY来做到这一点。问题是GROUP BY:

SELECT ar.account_no, ah.created_t, ah.bal_acct
FROM VD_REPLICA_BRM.pi_tp_acct_ar_t ar JOIN
     VD_REPLICA_BRM.pi_tp_acct_ar_hist_T ah
     ON ah.obj_id0 = ar.poid_Id0 JOIN
     VD_REPLICA_BRM.pi_account_t acc
     ON acc.poid_id0 = ar.account_obj_Id0
WHERE acc.account_no = '00003095660515' AND
      ah.created_t <= CAST('2016-10-31' AS DATE FORMAT 'YYYY-MM-DD')
QUALIFY ROW_NUMBER() OVER( PARTITION BY ar_account_no ORDER BY ah.created_t desc) = 1