On 14/11/11 18:35, Amit Dor-Shifer wrote:
On Mon, Nov 14, 2011 at 4:29 PM, Amit Dor-Shifer
<amit.dor.shifer@gmail.com> wrote:
Hi,
I've got this table:
create table phone_calls
(
start_time timestamp,
device_id integer,
term_status integer
);
[…]
3 points
POINT 1:
I should have given the results of my attempt...
[...]
device_id
-----------
2
40
50
60
(4 rows)
POINT 2:
I also realized I left of a condition in the HAVBING part
HAVING
max(pc1.start_time) >= min(pc1.start_time) + interval '2 minute'
I think it should be
HAVING
max(pc1.start_time) >= min(pc1.start_time) + interval '2 minute'
AND pc1.term_status = 2
POINT 3:
Timestamps should almost always be stored with a time zone (using timestamptz rather than just timestamp) – or you will have problems when Summer time ends or begins, and using timestamptz allows for date&time to be displayed currectly in different locales.
Regards,
Gavin
P.S. Since my post has not shown up yet, I had to attach to its parent!
(I won't offer my first born to get direct posting rights,
as his wife may object -
besides which, it is probably illegal in my jurisdiction!)
