php实现网站查询功能实现的

PHP实现网站查询功能的方法

数据库连接与配置

使用PDO或mysqli扩展连接数据库，确保安全性。示例代码：

$host = 'localhost';
$dbname = 'database_name';
$username = 'username';
$password = 'password';

try {
    $pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    die("Connection failed: " . $e->getMessage());
}

接收用户输入

通过HTML表单获取用户查询条件，使用POST或GET方法传递参数：

<form method="GET" action="search.php">
    <input type="text" name="search_term" placeholder="输入关键词">
    <button type="submit">搜索</button>
</form>

处理查询请求

在PHP脚本中处理用户输入，注意SQL注入防护：

$searchTerm = isset($_GET['search_term']) ? trim($_GET['search_term']) : '';

if (!empty($searchTerm)) {
    $stmt = $pdo->prepare("SELECT * FROM products WHERE name LIKE :term OR description LIKE :term");
    $stmt->bindValue(':term', '%' . $searchTerm . '%');
    $stmt->execute();
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);
}

显示查询结果

将查询结果以表格或其他形式展示给用户：

if (!empty($results)) {
    echo '<table>';
    echo '<tr><th>ID</th><th>名称</th><th>描述</th></tr>';
    foreach ($results as $row) {
        echo '<tr>';
        echo '<td>' . htmlspecialchars($row['id']) . '</td>';
        echo '<td>' . htmlspecialchars($row['name']) . '</td>';
        echo '<td>' . htmlspecialchars($row['description']) . '</td>';
        echo '</tr>';
    }
    echo '</table>';
} else {
    echo '没有找到匹配的结果';
}

高级查询功能实现

对于复杂查询，可以添加多条件筛选：

$category = isset($_GET['category']) ? $_GET['category'] : '';
$price_min = isset($_GET['price_min']) ? (float)$_GET['price_min'] : 0;
$price_max = isset($_GET['price_max']) ? (float)$_GET['price_max'] : PHP_FLOAT_MAX;

$sql = "SELECT * FROM products WHERE (name LIKE :term OR description LIKE :term)";
$params = [':term' => '%' . $searchTerm . '%'];

if (!empty($category)) {
    $sql .= " AND category = :category";
    $params[':category'] = $category;
}

$sql .= " AND price BETWEEN :price_min AND :price_max";
$params[':price_min'] = $price_min;
$params[':price_max'] = $price_max;

$stmt = $pdo->prepare($sql);
$stmt->execute($params);

分页功能实现

处理大量数据时添加分页支持：

$per_page = 10;
$page = isset($_GET['page']) ? (int)$_GET['page'] : 1;
$offset = ($page - 1) * $per_page;

$stmt = $pdo->prepare("SELECT SQL_CALC_FOUND_ROWS * FROM products WHERE name LIKE :term LIMIT :offset, :per_page");
$stmt->bindValue(':term', '%' . $searchTerm . '%');
$stmt->bindValue(':offset', $offset, PDO::PARAM_INT);
$stmt->bindValue(':per_page', $per_page, PDO::PARAM_INT);
$stmt->execute();

$total = $pdo->query("SELECT FOUND_ROWS()")->fetchColumn();
$total_pages = ceil($total / $per_page);