使用 PHP while 循环创建高级过滤器

Question

我有一个问题，那就是我想在网站上创建一个链接，就像人们可以单击该链接以仅根据百分比显示某些产品一样。 例如，我的数据库中有一列包含折扣百分比，它将显示最小折扣和最大折扣。 假设我们有最小和最大折扣。 $min=12 和 $max=94; 我想把它们放在链接中只显示具有某些折扣的产品只喜欢过滤。下面是链接的示例。

    <a href="#">12% to 20%</a
    <a href="#">21% to 30%</a>
    <a href="#">31% to 40%</a> and so on until it reaches 
    <a href="#">81% to 90%</a> and the last will be 
    <a href="#">91% to 94%</a>

最小和最大的数字将来自数据库中的列，它们可以经常更改。 我想出了解决方案，它工作正常，但我的代码太长了，就像我采取了许多步骤，可以在几行代码中完成。我已经在下面粘贴了我的工作代码，但我相信这可以减少到几行代码。

$catsql25 = "SELECT MAX(down_percentage) as largest FROM hot_deals";
$catquery25 = mysqli_query($conn, $catsql25);
while ($row25 = mysqli_fetch_array($catquery25, MYSQLI_ASSOC)){
    $largest_number = $row25['largest'];
}
$catsql26 = "SELECT MIN(down_percentage) as smallest FROM hot_deals";
$catquery26 = mysqli_query($conn, $catsql26);
while ($row26 = mysqli_fetch_array($catquery26, MYSQLI_ASSOC)){
    $smallest_number = $row26['smallest'];
}
$array_tens = array(10,20,30,40,50,60,70,80,90,100);

foreach ($array_tens as $value){
    if(($value - $smallest_number <= 10) && ($value - $smallest_number > 0)){
        echo '<a href="/exp.php?fst='.$smallest_number.'&lst='.$value.'"><div class="lfmen2">';
        echo $smallest_number." to ".$value."</div></a>";
        $next_num = $value + 1;
        $next_ten = 9;
        $stop_num = floor($largest_number / 10);
        $stop_num2 = $stop_num * 10;
        //echo $stop_num2.'<br>';
        $num_rounds = $stop_num2 - $value;
        $num_rounds2 = $num_rounds / 10;
        //echo $num_rounds2;
        for ($i = 1; $i <= $num_rounds2; $i++){
        $end_num = $next_num + $next_ten;
        echo '<a href="/exp.php?fst='.$next_num.'&lst='.$end_num.'"><div class="lfmen2">';
        echo $next_num;
        echo " to ";
        echo $end_num;
        echo "</div></a>";
        $next_num += 10;
        $end_num += 10;
        }
    }
}

foreach ($array_tens as $value2){
    if(($largest_number - $value2 < 10) && ($largest_number - $value2 > 0)){
        $lsst = $value2 + 1;
        if($lsst != $largest_number){
        echo '<a href="/exp.php?fst='.$lsst.'&lst='.$largest_number.'"><div class="lfmen2">'.$lsst." to ".$largest_number."</div></a>";
        }
        elseif($lsst == $largest_number){
            echo '<a href="/exp.php?fnly='.$largest_number.'"><div class="lfmen2">'.$largest_number.'</div></a>';
        }
    }
}

我知道这都是一团糟，但是..谢谢。

Answer 1

你可以做的第一件事只有一个SQL查询：

$catsql = "SELECT MAX(down_percentage) as largest, MIN(down_percentage) as smallest FROM hot_deals";

然后你只需要一个循环：

$catquery = mysqli_query($conn, $catsql);
while ($row = mysqli_fetch_array($catquery, MYSQLI_ASSOC)){
    $largest_number = $row['largest'];
    $smallest_number = $row['smalest'];
}

之后，您只能创建一个 foreach 循环。两个"如果"条件可以在同一循环中：

foreach ($array_tens as $value) {
    if (($value - $smallest_number <= 10) && ($value - $smallest_number > 0)) {
        echo '<a href="/exp.php?fst='.$smallest_number.'&lst='.$value.'"><div class="lfmen2">';
        echo $smallest_number." to ".$value."</div></a>";
        $next_num = $value + 1;
        $next_ten = 9;
        $stop_num = floor($largest_number / 10);
        $stop_num2 = $stop_num * 10;
        //echo $stop_num2.'<br>';
        $num_rounds = $stop_num2 - $value;
        $num_rounds2 = $num_rounds / 10;
        //echo $num_rounds2;
        for ($i = 1; $i <= $num_rounds2; $i++) {
            $end_num = $next_num + $next_ten;
            echo '<a href="/exp.php?fst='.$next_num.'&lst='.$end_num.'"><div class="lfmen2">';
            echo $next_num;
            echo " to ";
            echo $end_num;
            echo "</div></a>";
            $next_num += 10;
            $end_num += 10;
        }
    }
    if (($largest_number - $value < 10) && ($largest_number - $value > 0)) {
        $lsst = $value + 1;
        if ($lsst != $largest_number) {
            echo '<a href="/exp.php?fst='.$lsst.'&lst='.$largest_number.'"><div class="lfmen2">'.$lsst." to ".$largest_number."</div></a>";
        } elseif ($lsst == $largest_number) {
            echo '<a href="/exp.php?fnly='.$largest_number.'"><div class="lfmen2">'.$largest_number.'</div></a>';
        }
    }
}

为了使其更具可读性，您还可以注释代码以了解什么做什么。

这和一个很好的缩进，你是对的。

希望对您有所帮助。