MySQLのビューと現在と前の行の間の数学

Question

私は、太陽光充電コントローラからMySQLデータベース（5.5.52）にデータを収集しています。これまでのところ、私はテーブルを持って、レジスタ：

mysql> SELECT date,time,panelVoltage,panelCurrent,batteryVoltage,loadCurrent 
    FROM registers 
    ORDER BY date,time 
    LIMIT 4; 
+------------+----------+--------------+--------------+----------------+-------------+ 
| date  | time  | panelVoltage | panelCurrent | batteryVoltage | loadCurrent | 
+------------+----------+--------------+--------------+----------------+-------------+ 
| 2016-11-27 | 17:20:41 |  26.04 |   1.31 |   25.15 |  0.72 | 
| 2016-11-27 | 17:21:06 |  26.06 |   1.31 |   25.15 |  0.76 | 
| 2016-11-27 | 17:21:32 |  26.06 |   1.15 |   25.16 |   0.6 | 
| 2016-11-27 | 17:21:57 |  26.06 |   1.3 |   25.16 |  0.68 | 
+------------+----------+--------------+--------------+----------------+-------------+ 

私は私が思うVIEWとしてパネルや負荷のためにワットの時間を計算したいと思いますので、それが最新の状態に保ちます。 （非常に）擬似コード：

SELECT (panelVoltage * panelCurrent) as panelWattage, 
    CONCAT(date, ' ', time) AS datetime 
    FROM registers ORDER BY datetime; 
timeDiff = (currRow.datetime from prevRow.datetime)/3600 # for time decimal hours 
powerSum = (currRow.panelWattage + prevRow.panelWattage)/2 # for average Wattage 
Wh = timeDiff * powerSum # for Watt-hours 

だから、ビュー/列がpanelWhとloadWhを保持し、多分それぞれの実行中の合計、panelWhSum、loadWhSumでしょう。

$qry = "SELECT CONCAT(date,' ',time) as datetime,loadCurrent,batteryVoltage,panelCurrent,panelVoltage, 
    panelCurrent * panelVoltage as 'panelWatt', loadCurrent * batteryVoltage as 'loadWatt' FROM registers 
    WHERE TIMESTAMP(`date`, `time`) > NOW() - INTERVAL ".$_GET['time']." MINUTE"; 
    $result = mysqli_query($con,$qry); 
    $table = array(); 
    $table['cols'] = array(
    array('label' => 'datetime', 'type' => 'datetime'), 
    array('label' => 'panel Wh', 'type' => 'number'), 
    array('label' => 'load Wh', 'type' => 'number'), 
    array('label' => 'net Wh', 'type' => 'number') 
    foreach($result as $row){ 
    $prevTime = $curTime; 
    $curTime = $datetime; 
    $prevPW = $curPW; 
    $curPW = $row['panelWatt']; 
    $prevLW = $curLW; 
    $curLW = $row['loadWatt']; 
    if ($i == 0) { 
     $prevTime = $datetime; 
     $prePW = $row['panelWatt']; 
     $preLW = $row['loadWatt']; 
    } 
    $diffInSeconds = $curTime->getTimestamp() - $prevTime->getTimestamp(); 
    $panelWh = ($diffInSeconds * 0.5 * ($prevPW + $curPW)/3600); 
    $panelWhTotal = $panelWhTotal + $panelWh; 
    $loadWh = ($diffInSeconds * 0.5 * ($prevLW + $curLW)/3600); 
    $loadWhTotal = $loadWhTotal + $loadWh; 
    $temp[] = array('v' => (float) round($panelWhTotal, 2)); 
    $temp[] = array('v' => (float) round($loadWhTotal, 2)); 
    $temp[] = array('v' => (float) round(($panelWhTotal - $loadWhTotal), 2)); 
    } 

は、上記のPHPコードからの例をグラフ化： panel, load Watt-hours

Answer 1

を私はあなたを示唆私は理解ビューは道、より効率的である - ここで

は私のPHPコードだけではやっています次のような表。私はあなたが