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? -- gor...@gmail.com Mob: 070-5530148
