How to calculate totals - Joomla! Forum - community, help and support

i have table looks this:

code: select all

office |        start        |         end         | total
------------------------------------------------------------
nyc    | 2014-07-01 20:56:00 | 2014-07-01 22:19:00 | 01:23 |
ewi    | 2014-07-17 17:35:00 | 2014-07-17 18:05:00 | 00:30 |
nyc    | 2014-07-11 03:09:00 | 2014-07-11 03:26:00 | 00:17 |
------------------------------------------------------------

so, shows when office had downtime , how long lasted. how calculate (add) total time "nyc" office only? so, want output 01:40 (combined 01:23 + 00:17).

my query looks this:

code: select all

$query->select($db->quotename(array('id', 'office', 'start', 'end', 'total')));
$query->from($db->quotename('#__outage'));

excellent question!

here's query:

code: select all

select office, sec_to_time(sum(time_to_sec(`total`))) `total_downtime_office` `your_table` group office;