Question

I have a worklog table that contains the following fields:

worklog_id,
agent_name,
ticket_number,
timestamp,
worklog_notes.  

I would like to be able to count the number of worklog entries made where if the agent_name, ticket_number and timestamp (date) are the same the worklog entry is only counted if the time between the two entries is greater than 1 hour.

Example: John Smith make three worklog entries on ticket 12345. The first timestamp is “10/11/2012 9:11:44 AM”, the second timestamp is “10/11/2012 9:36:16 AM” and the third timestamp is “10/11/2012 11:18:20 AM”. In this example I would only want to give the agent credit for two worklog entries as the first two were less than an hour apart.

I’ve tried getting the logic to work using a “where” sub-query, but cannot get it working. Would anyone have any example they could provide? Thanks! 🙂

Answer 1

Does this get what you want? The first entry by a given agent on a ticket should always be counted, and entries after that should only be counted if at least an hour has elapsed since the prior entry.

select agent_name, ticket_number, count(*) from (
  select agent_name, ticket_number, timestamp,
         lag(timestamp) over
            (partition by agent_name, ticket_number order by timestamp) prev_timestamp
  )
from worklog
where (prev_timestamp is null
       or (timestamp - prev_timestamp) >= interval '1' hour
      )
group by agent_name, ticket_number

I’m not sure this is exactly what you want — if an agent keeps adding entries within an hour of the prior entry, none of them will be counted except the first. So someone who adds a lot of updates gets penalized.

Maybe what you really want is to count the number of distinct hours in which an update was made:

select agent_name, ticket_number, count(distinct to_char(timestamp,'DD-MON-YYYY HH24')
  from worklog
  group by agent_name, ticket_number