Hello all!
I am logging my electricity meeter every five minute!
But the problem is that I would like to get values *just before* every hour - like
select * from counter_log_view where name='CNT-3' and timestamp < '2010-05-23 22:00:00' order by timestamp desc limit 1;
name | timestamp | count
-------+----------------------------+-------
CNT-3 | 2010-05-23 21:53:20.844422 | 69
(1 rad)
But I don't want to do a lot of selections and gather all the data in a file.
Is there any better way to create the query so that I get the values just before
every hour?
I would like to do;
freescada=> select * from counter_log_view where name='CNT-3' and timestamp < '2010-05-23 18:00:00' order by timestamp desc limit 1;
name | timestamp | count
-------+---------------------------+-------
CNT-3 | 2010-05-23 17:53:18.58674 | 43
(1 rad)
freescada=> select * from counter_log_view where name='CNT-3' and timestamp < '2010-05-23 19:00:00' order by timestamp desc limit 1;
name | timestamp | count
-------+----------------------------+-------
CNT-3 | 2010-05-23 18:53:19.151988 | 50
(1 rad)
freescada=> select * from counter_log_view where name='CNT-3' and timestamp < '2010-05-23 20:00:00' order by timestamp desc limit 1;
name | timestamp | count
-------+----------------------------+-------
CNT-3 | 2010-05-23 19:53:19.683514 | 51
(1 rad)
In one query. Is this possible in *any* way?
--
gorhas@xxxxxxxxx
Mob: 070-5530148
