Question

我有下表：

ID          DESCRIPTION                 TIMESTAMP
1            RECEIVER                    00:10:00
1            SENDER                      00:08:00
1            EXECUTOR                    00:05:00
1            SENDER                      00:03:00

如何获取最新“ SENDER”描述，并使用我的时间戳找到另一个描述的时差？

我想找到SENDER和EXECUTOR之间的时差，但由于它同时拾取了SENDER和SENDER项，因此我得到了奇怪的结果。

谢谢亚当

Answer 1

SELECT
    t1.timestamp - t2.timestamp
from
    (SELECT 
        timestamp 
    FROM 
        table 
    WHERE 
        description='SENDER' 
    ORDER BY timestamp DESC LIMIT 1) t1,
    table t2
WHERE
    t2.description = 'your_description'

Answer 2

您可以通过使用lag和row_number函数来使用这样的机制：

select id, timestamp_diff
  from
(
  with t(ID,DESCRIPTION,TIMESTAMP) as
  (
   select 1,'RECEIVER',to_timestamp('00:10:00','HH24:MI:SS') from dual union all
   select 1,'SENDER',to_timestamp('00:08:00','HH24:MI:SS') from dual union all
   select 1,'EXECUTOR',to_timestamp('00:05:00','HH24:MI:SS') from dual union all
   select 1,'SENDER',to_timestamp('00:03:00','HH24:MI:SS') from dual 
  )
   select t.id, 
          t.timestamp - lag(t.timestamp) over (order by t.timestamp desc) as timestamp_diff,
          row_number() over (order by t.timestamp) as rn 
     from t   
    where t.description = 'SENDER'
)
where rn = 1;

 ID    TIMESTAMP_DIFF
 -- --------------------
 1  -000000000 00:05:00

对于多个ID，请考虑使用以下ID：

select id , max(timestamp_diff) as timestamp_diff
  from
  (
    with t(ID,DESCRIPTION,TIMESTAMP) as
    (
     select 1,'RECEIVER',to_timestamp('00:10:00','HH24:MI:SS') from dual union all
     select 1,'SENDER',to_timestamp('00:08:00','HH24:MI:SS') from dual union all
     select 1,'EXECUTOR',to_timestamp('00:05:00','HH24:MI:SS') from dual union all
     select 1,'SENDER',to_timestamp('00:03:00','HH24:MI:SS') from dual union all
     select 2,'SENDER',to_timestamp('00:06:00','HH24:MI:SS') from dual union all
     select 2,'SENDER',to_timestamp('00:02:00','HH24:MI:SS') from dual 
    )
     select t.id, 
            t.timestamp - lag(t.timestamp) over 
            (partition by t.id order by t.id,t.timestamp desc) as timestamp_diff,
            row_number() over (order by t.id,t.timestamp) as rn,
            t.description 
       from t   
      where t.description = 'SENDER'
  )  
  group by id, description;

 ID    TIMESTAMP_DIFF
 -- --------------------
 1  -000000000 00:05:00
 2  -000000000 00:04:00

SQL获取带有时间戳的最新重复条目

2 个答案: