Question

是否可以从下面类似的3段创建1段代码？

每个段落之间的区别是：
* SQL查询WHERE模型= $
* $系列？ = new XYDataSet（）
* addSerie（“Model”，$ serie ??）
* $ serie ?? - ＆gt; addPoint

$chart = new LineChart(1800, 500);
$dataSet = new XYSeriesDataSet();

$sql = mysql_query("SELECT Date, SUM(Qty_sum) AS Qty_sum FROM stats WHERE Model = 'ESD' GROUP BY MONTH(Date)");
    $serie1 = new XYDataSet();
    $dataSet->addSerie("ESD", $serie1);

        while($row = mysql_fetch_assoc($sql)) {
            $date = date('M', strtotime($row['Date']));
            $qty = $row['Qty_sum'];

            $serie1->addPoint(new Point("$date", $qty));
        }


$sql2 = mysql_query("SELECT Date, SUM(Qty_sum) AS Qty_sum FROM stats WHERE Model = 'POSA' GROUP BY MONTH(Date)");           
    $serie2 = new XYDataSet();
    $dataSet->addSerie("POSA", $serie2);

        while($row = mysql_fetch_assoc($sql2)) {
            $date = date('M', strtotime($row['Date']));
            $qty = $row['Qty_sum'];

            $serie2->addPoint(new Point("$date", $qty));
        }


$sql3 = mysql_query("SELECT Date, SUM(Qty_sum) AS Qty_sum FROM stats WHERE Model = 'POSA MM/SAT' GROUP BY MONTH(Date)");            
    $serie3 = new XYDataSet();
    $dataSet->addSerie("POSA MM/SAT", $serie3);

        while($row = mysql_fetch_assoc($sql3)) {
            $date = date('M', strtotime($row['Date']));
            $qty = $row['Qty_sum'];

            $serie3->addPoint(new Point("$date", $qty));
        }           


$chart->setDataSet($dataSet);

Answer 1

如果您创建一个数组，

$things = ['ESD', 'POSA', 'POSA MM/SAT'];

您可以循环访问代码3次，并在必要时替换值。

即

foreach($things as $thing){
    $sql = mysql_query("SELECT Date, SUM(Qty_sum) AS Qty_sum FROM stats WHERE Model = '" . $thing . "' GROUP BY MONTH(Date)"); 
    $series[$thing] = new XYDataSet();
    $dataSet->addSerie($thing, $series[$thing]);

    while($row = mysql_fetch_assoc($sql)) {
        $date = date('M', strtotime($row['Date']));
        $qty = $row['Qty_sum'];

        $series[$thing]->addPoint(new Point("$date", $qty));
    }
}

Answer 2

以下是我在一次SQL查询过程中编写代码的方法。

$chart = new LineChart(1800, 500);
$dataSet = new XYSeriesDataSet();

使模型成为一个数组，在一个地方声明。

$models = ['ESD', 'POSA', 'POSA MM/SAT'];

为每个模型创建一个系列数组并初始化数据集对象。

$series = [];
foreach ($models as $model) {
    $series[$model] = new XYDataSet();
}

使用PDO，以便在SQL中使用参数化的IN()谓词。每个模型需要一个占位符，因此根据$ models数组的大小生成占位符列表。

我也在SQL中进行日期格式化（参见http://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format）

$placeholders = implode(",", array_fill(1, count($models), "?"));
$stmt = $pdo->prepare("
    SELECT Model, DATE_FORMAT(Date, '%b') AS Mon, SUM(Qty_sum) AS Qty_sum 
    FROM stats 
    WHERE Model IN ($placeholders)
    GROUP BY Model, Mon");

很容易将模型数组传递给准备好的查询，以匹配SQL查询中的占位符。

$stmt->execute($models);

结果集将按模型和按月分组。

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    $point = new Point($row['Mon'], $row['Qty_sum']));
    $series[$row['Model']]->addPoint($point);
}

对于还是Foreach？

2 个答案: