排除组 SQL Teradata 中特定列值之前的行

Question

我在 Teradata 中有以下结构的 table。我的分析在数据上传后开始，即状态列中的状态为 'UPLOADED'。我想排除每个组中状态变为 'UPLOADED' 之前的行。所有事件都是实时发生的，即每个新事件的时间戳值都会增加。

输入table数据-->table_input

ID  STATUS      TMP
A1  UPLOADED    06/16/2021 08:38:44.535
A1  A           06/16/2021 16:20:40.014
A1  (B)         06/16/2021 17:15:36.488
A1  C           06/16/2021 17:15:36.846
A1  A           06/16/2021 17:15:36.883
B1  A2          06/16/2021 08:34:09.974
B1  L           06/16/2021 08:34:10.271
B1  L           06/16/2021 14:44:33.677
B1  (R)         06/16/2021 14:52:21.812
B1  UPLOADED    06/16/2021 16:05:36.346
B1  AP          06/16/2021 16:05:36.499
B1  (R)         06/16/2021 16:05:36.718
C1  C           06/16/2021 16:05:36.764
C1  UPLOADED    06/16/2021 08:49:43.796
C1  UPLOADED    06/16/2021 08:49:43.841
C1  L           06/16/2021 14:50:39.667
C1  UPLOADED    06/16/2021 14:52:50.149
C1  (R)         06/16/2021 16:05:43.998

预期输出：结果中排除了状态为 'UPLOADED' 之前的数据。

ID  STATUS      TMP
A1  UPLOADED    06/16/2021 08:38:44.535
A1  A           06/16/2021 16:20:40.014
A1  (B)         06/16/2021 17:15:36.488
A1  C           06/16/2021 17:15:36.846
A1  A           06/16/2021 17:15:36.883
B1  UPLOADED    06/16/2021 16:05:36.346
B1  AP          06/16/2021 16:05:36.499
B1  (R)         06/16/2021 16:05:36.718
C1  UPLOADED    06/16/2021 08:49:43.796
C1  UPLOADED    06/16/2021 08:49:43.841
C1  L           06/16/2021 14:50:39.667
C1  UPLOADED    06/16/2021 14:52:50.149
C1  (R)         06/16/2021 16:05:43.998

我正在使用 Teradata SQL，但 SQL 服务器 SQL 应该也可以。我正在尝试使用 window 函数，但还没有取得任何成功。我们还可以将 TMP 列与 TimeStamp 一起使用并编写逻辑代码，例如排除 TimeStamp 值小于 TimeStamp of First occurrence of 'UPLOADED'.

的所有行

Answer 1

您可以在 Teradata 中使用 qualify 子句：

select t.*
from t
qualify tmp >= min(case when status = 'UPLOADED' then tmp end) over (partition by id);

而且，虽然您可以为此使用 window 函数，但也可以使用相关子查询来编写它：

select t.*
from t
where t.tmp > (select min(t2.tmp)
               from t t2
               where t2.id = t.id and t2.status = 'UPLOADED'
              );

排除组 SQL Teradata 中特定列值之前的行

Exclude rows that come before a specific column value in group SQL Teradata

sql

sql-server

teradata

window-functions