sql - 获取每个 TIMESTAMP 的最新记录

Question

我有这个查询：

SELECT TIMESTAMP, 
       TIMESTAMP_OFFER, 
       TIMESTAMP_TRACK, 
       STATUS_ACPT 
FROM   TABLE1 
WHERE  TIMESTAMP IN 
(
    SELECT TIMESTAMP 
    FROM   TABLE2 
    WHERE  STATUS = '1' 
    AND    TIMESTAMP_PROCESSED BETWEEN 
            '2017-01-07-00.00.00.000000' 
        AND '2017-01-17-00.00.00.000000'
)

结果：

    ---------------------------------------------------------------------------------------------------------
    | TIMESTAMP                  | TIMESTAMP_OFFER               | TIMESTAMP_TRACK            | STATUS_ACPT |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-09 11:26:29.434254  | 2017-01-25 14:36:23.587199    | 2017-01-25 14:36:23.587199 | P           |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-09 11:26:29.434254  | 2017-02-01 16:05:02.221179    | 2017-02-01 16:05:02.221179 | P           |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-09 11:26:29.434254  | 2017-02-01 16:05:02.221179    | 2017-07-13 10:59:20.342584 | E           |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-11 15:09:51.935322  | 2017-02-11 12:00:50.410959    | 2017-02-11 12:00:50.410959 | P           |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-11 15:09:51.935322  | 2017-02-11 12:00:50.410959    | 2017-02-11 12:10:50.410959 | A           |
    ---------------------------------------------------------------------------------------------------------

我需要每个 TIMESTAMP 的最新记录，我应该得到这个：

    ---------------------------------------------------------------------------------------------------------
    | TIMESTAMP                  | TIMESTAMP_OFFER               | TIMESTAMP_TRACK            | STATUS_ACPT |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-09 11:26:29.434254  | 2017-02-01 16:05:02.221179    | 2017-07-13 10:59:20.342584 | E           |
    ---------------------------------------------------------------------------------------------------------
    |2017-01-11 15:09:51.935322  | 2017-02-11 12:00:50.410959    | 2017-02-11 12:10:50.410959 | A           |
    ---------------------------------------------------------------------------------------------------------

我如何得到它？

如您所见，TIMESTAMP 和 TIMESTAMP_OFFER 可以有重复的值，但 TIMESTAMP_TRACK 是唯一的。

Answer 1

假设 table1 是上面显示的结果表，您可以使用以下查询解决它：

with temp as (
select timestamp, timestamp_offer, timestamp_track, status_acpt,
       row_number() over (order by timestamp desc) as rownum_timestamp,
       row_number() over (order by timestamp_offer desc) as rownum_timestamp_offer
  from table1)
  select timestamp, timestamp_offer, timestamp_track
    from temp
   where rownum_timestamp = 1 or rownum_timestamp_offer = 1

公用表表达式用于添加行号 - 每个时间戳列对应一个您需要的最大值，并且在主 SQL 语句中仅检索行号 = 1 的行。请注意排序顺序 - 它是降序的，因此第 1 行是最大时间戳。