php - php中的粘性下拉框问题

Question

我正在尝试创建一个粘性下拉选项框。但每次我单击提交按钮时，该值都不会保留。它改变。

我做错了什么？

    <select name=person >
       <option value="NULL">Choose a person</option>';
    <?php $dbc = getDBC ();
          $result = $dbc->query('SELECT * from person');
          while ($row = $result->fetch_assoc()) {
          echo "<option value=\"$row[ID]\"";
         if (isset($_POST['person']) && ($_POST['person'] == $row[ID])) {
          echo 'selected="selected"';
         }
    echo ">($row[ID]) &nbsp $row[FIRST_NAME] &nbsp $row[LAST_NAME]</option>\n";
      }   
      ?>
</select>

Answer 1

尝试下面的代码，我做了一些语法更改。您还可以使用 where 条件 SELECT * from person where id = $_POST['person']

来优化它

<select name=person >
           <option value="NULL">Choose a person</option>';
           <?php 
                $dbc = getDBC ();
                $result = $dbc->query('SELECT * from person');
                while ($row = $result->fetch_assoc()) {
                echo "<option value=\"$row['ID']\"";

                if (isset($_POST['person']) && $_POST['person'] == $row['ID']) {

                echo 'selected="selected"';
                }

                echo ">($row['ID']) &nbsp $row['FIRST_NAME'] &nbsp $row['LAST_NAME']</option>\n";

               }   

               ?>
           </select>