Re: join on next row

It would have been quite easy if done in Oracle's 'lateral view'
feature. But I think it is achievable in standard SQL too; using
subqueries in the select-clause.

Try something like this:

select
Employee, EventDate,
EventTime as e1_time,
EventType as e1_type,
( select
EventTime
from
Events
where Employee = O.Employee
and EventDate = O.EventDate
and EventTime > O.EventTime
limit 1
)as e_time_1,
( select
EventType
from
Events
where Employee = O.Employee
and EventDate = O.EventDate
and EventTime > O.EventTime
limit 1
)
from
Events

Hope it helps...

Regards,
Gurjeet.

On 6/20/06, Sim Zacks <sim(at)compulab(dot)co(dot)il> wrote:
> I am having brain freeze right now and was hoping someone could help me
> with a (fairly) simple query.
>
> I need to join on the next row in a similar table with specific criteria.
>
> I have a table with events per employee.
> I need to have a query that gives per employee each event and the event
> after it if it happened on the same day.
>
> The Events table structure is:
>
> EventID
> Employee
> EventDate
> EventTime
> EventType
>
> I want my query resultset to be
> Employee,EventDate(1),EventTime(1),EventType(1),EventTime(2),EventType(2)
> Where Event(2) is the first event of the employee that took place after
> the other event.
>
> Example
> EventID Employee EventDate EventTime EventType
> 1 John 6/15/2006 7:00 A
> 2 Frank 6/15/2006 7:15 B
> 3 Frank 6/15/2006 7:17 C
> 4 John 6/15/2006 7:20 C
> 5 Frank 6/15/2006 7:25 D
> 6 John 6/16/2006 7:00 A
> 7 John 6/16/2006 8:30 R
>
> Expected Results
> John, 6/15/2006, 7:00, A, 7:20, C
> Frank, 6/15/2006, 7:15, B, 7:17, C
> Frank, 6/15/2006, 7:17, C, 7:25, D
> John, 6/16/2006, 7:00, A, 8:30, R
>
> To get this result set it would have to be an inner join on employee and
> date where the second event time is greater then the first. But I don't
> want the all of the records with a greater time, just the first event after.
>
> Thank You
> Sim
>
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