实现下拉选择数据加载

Question

我正在尝试将数据库中的数据动态加载到表中，但这给我一个错误：

  

未定义索引：/xxx/xxx/xxx/search.php中第26行的条目

此外，通过登录浏览器控制台，我的选择无法识别onChange事件。

我以这个家庭教师为基础来实现自己的愿望：https://www.phpzag.com/ajax-drop-down-selection-data-load-with-php-mysql/

<?php
require('config/config.php');

if(isset($_SESSION['flash']))
{
    foreach($_SESSION['flash'] as $type => $message)
    {
        echo $message;
    }
    unset($_SESSION['flash']);
}

$output = '';
if(isset($_POST["query"]))
{
    $query = $cnx->prepare("SELECT * FROM candidacies WHERE lastName LIKE :lastName OR firstName LIKE :firstName OR age LIKE :age OR scheduleRange LIKE :scheduleRange OR phoneNumber LIKE :phoneNumber OR email LIKE :email OR candidacyType LIKE :candidacyType");
    $element = "%".$_POST['query']."%";
    $query->bindValue(':lastName', $element, PDO::PARAM_STR);
    $query->bindValue(':firstName', $element, PDO::PARAM_STR);
    $query->bindValue(':age', $element, PDO::PARAM_INT);
    $query->bindValue(':scheduleRange', $element, PDO::PARAM_STR);
    $query->bindValue(':phoneNumber', $element, PDO::PARAM_STR);
    $query->bindValue(':email', $element, PDO::PARAM_STR);
    $query->bindValue(':candidacyType', $element, PDO::PARAM_STR);
}
else if(isset($_POST['entries']))
{
    $entries = intval($_POST['entries']);
    $query = $cnx->prepare("SELECT * FROM candidacies LIMIT :entries");
    $query->bindValue(':entries', $entries, PDO::PARAM_INT);
}
else
{
    $limit_per_page = 10;

    $page = (!empty($_GET['page']) ? $_GET['page'] : 1);
    $start = ($page - 1) * $limit_per_page;

    $query = $cnx->prepare("SELECT SQL_CALC_FOUND_ROWS * FROM candidacies LIMIT :limit_per_page OFFSET :start");
    $query->bindValue(':limit_per_page', $limit_per_page, PDO::PARAM_INT);
    $query->bindValue(':start', $start, PDO::PARAM_INT);

    //$query = $cnx->prepare('SELECT * FROM candidacies');
}

$query->execute();
$result = $query->fetchAll(PDO::FETCH_ASSOC);
$count = $query->rowCount();

$resultFoundRows = $cnx->prepare('SELECT found_rows()');
$resultFoundRows->execute();
$listElements = $resultFoundRows->fetchColumn();

if($count > 0)
{
    $output .= '
        <select name="entriesData" class="entriesData">
            <option value="2">2</option>
            <option value="10">10</option>
            <option value="20">20</option>
            <option value="50">50</option>
            <option value="100">100</option>
        </select>
    ';

    $output .= '
        <table class="table table-striped" id="candidaciesTable">
        <thead class="thead-light">
            <tr>
                <th scope="col">firstName</th>
                <th scope="col">lastName</th>
                <th scope="col">Âge</th>
                <th scope="col">Schedule Range</th>
                <th scope="col">Phone Number</th>
                <th scope="col">Email</th>
                <th scope="col">Candidacy Type</th>
                <th scope="col">Action</th>
            </tr>
        </thead>
        <tbody>
    ';
    foreach($result as $key => $value)
    {
        $output .= "
            <tr>
                <td>".htmlspecialchars($value["firstName"])."</td>
                <td>".htmlspecialchars($value["lastName"])."</td>
                <td>".htmlspecialchars($value["age"])."</td>
                <td>".htmlspecialchars($value["scheduleRange"])."</td>
                <td>".htmlspecialchars($value["phoneNumber"])."</td>
                <td>".htmlspecialchars($value["email"])."</td>
                <td>".htmlspecialchars($search["candidacyType"])."</td>
                <td>
                    <div class='btn-group'>
                        <button class='btn btn-light btnViewCandidacy' id=".$value['id'].">
                            <i class='far fa-eye'></i>
                        </button>
                        <button class='btn btn-info' id='btnEditCandidacy' onclick='editCandidacy(".$value['id'].")'>
                            <i class='far fa-edit'></i>
                        </button>
                        <button class='btn btn-danger' id='btnDeleteCandidacy' onclick='deleteCandidacy(".$value['id'].")'>
                            <i class='far fa-trash-alt'></i>
                        </button>
                    </div>
                </td>
            </tr>
        ";
    }
    $output .= "
            </tbody>
        </table>";
}
else
{
    echo "No results found !";
}
?>
<script>
$(document).ready(function()
{
    $('.entriesData').change(function()
    {
        var entriesData = $(this).find(":selected").val();
       var entries = 'entries='+ entriesData;
       $.ajax({
           url: "search.php",
           method:"POST",
           data:entries,
           success:function(data)
           {
               $('#result').html(data);
           }
        })
    });
});
</script>
<div id="result"></div>