如何计算事件的总时间（以分钟计），在一小时内发生了很多次，在Msql和php中每个小时

Question

I am hanged in a problem may be due to my lack of expertise. I have following mysql table:

Fdname -- fcode - timestate - Status

University 104 2015-03-05 01:37:00 OFF

University 104 2015-03-05 01:42:00 ON

University 104 2015-03-05 01:55:00 OFF

University 104 2015-03-05 02:00:00 ON

University 104 2015-03-05 07:20:00 OFF

University 104 2015-03-05 07:22:00 ON

University 104 2015-03-05 10:17:00 OFF

University 104 2015-03-05 11:16:00 ON

University 104 2015-03-05 12:17:00 OFF

University 104 2015-03-05 13:17:00 ON

University 104 2015-03-05 15:19:00 OFF

University 104 2015-03-05 16:16:00 ON

University 104 2015-03-05 18:16:00 OFF

University 104 2015-03-05 20:16:00 ON

University 104 2015-03-05 21:17:00 OFF

University 104 2015-03-05 22:18:00 ON

I need to calculate cumulative total minutes for each state 'OFF' and 'ON' per clock hour. ie i should know how many minutes a fname remains OFF within each hour. I tried a lot in php but could find any clue. ANy body can help or suggest in terms of query or php script. I will really appreciate.

Answer 1

Considering that $rs is the result of your appropriate query, I believe this will give you the result you're looking for.

$ontime = NULL;
$offtime = NULL;
$totalseconds = 0;

while($r = mysql_fetch_array($rs)){ 
    if($r["status"] == "OFF"){
        $offtime = strtotime($r["timestate"]);
    }
    if($r["status"] == "ON" AND $offtime !== NULL){
        $ontime = strtotime($r["timestate"]);
        $totalseconds += $ontime - $offtime;
        $offtime=NULL;
        $ontime=NULL; 
    }
}

$totalseconds will hold your total downtime in seconds