Re: Tricky SQL extraction question

since you are comparing rows in a table to other rows in the same table,
you might want to use WITH to first assign a row_number to each row within
Client:

with t1 as (
select a.client, a.startDate, a.endDate,
row_number() over ( partition by a.client order by a.startDate) rownum
from client_date_table a
}
select a.client, a.startDate, a.endDate, a.rownum
from t1 a
where ....


On Wed, Dec 20, 2023 at 12:27 PM Dave <dfx1@xxxxxxxxxxxxxx> wrote:

Hi,

I never thought I would need to make a request and SQL could not help
me, but I can't see how I could use it here.
Any ideas how I can accomplish this? In the exemple, I need to extract
clients C3 and C4. C3 because one of the periods overlap; C4 because the
2nd period does not immediately follow the 1st one.

Client StartDate EndDate
C1 2023-05-31
C2 2023-01-01 2023-04-15
C2 2023-04-16 2023-12-31
C3 2023-02-28 2023-06-01
C3 2023-04-01
C4 2023-10-11 2023-11-13
C4 2023-11-15

Thanks!
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxxxxxxxxxx for any subscription related
questions.