如何在foreach循环(php)中按变量排序? - How can I sort by variable within a foreach loop (php)?

How can I sort by variable within a foreach loop (php)?

本文关键字：变量排序 php foreach 循环 | 更新日期: 2023-09-27

在我的每个循环中，我想根据变量$total resp的值对我的选项进行排序。data-total:

     <select>
                   <option data-total="0" value="" selected>--</option>
                   <?php 
                    $pdo = Database::connect();

                    $sql = "SELECT  *  FROM table_a;" ;
                    foreach ($pdo->query($sql) as $row) {
                            $a = $row['a'];
                            $number_a = $row['number_a'];               
                            $sql2 = "SELECT  *  FROM table_b WHERE a = '$a';" ;
                            $number_b = 0;
                            foreach ($pdo->query($sql2) as $row2) {
                                $number_b+= $row2['number']; 
                            }
                            $total = $number_a - $number_b;
                            echo '<option data-total="'.$total.'" value="'.$a.'">'.$a;
                    }
                    Database::disconnect();
                        ?>                                                          
     </select>

这可能吗?非常感谢!

在for循环中执行如下操作

$total_arr = array();
foreach ($pdo->query($sql) as $row) {
                            $a = $row['a'];
                            $number_a = $row['number_a'];               
                            $sql2 = "SELECT  *  FROM table_b WHERE a = '$a';" ;
                            $number_b = 0;
                            foreach ($pdo->query($sql2) as $row2) {
                                $number_b+= $row2['number']; 
                            }
                            $total = $number_a - $number_b;
                            $total_arr[$a] = $total;
                    }
arsort($total_arr);
foreach ($total_arr as $key => $val) {
    echo '<option data-total="'.$val.'" value="'.$key.'">'.$key;
}