PHP/MySql选择与回复分组的注释

<?php
// 连接MySQL数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// 执行查询操作
$sql = "SELECT * FROM myTable";
$result = $conn->query($sql);

// 遍历查询结果，并将每个结果分组
$grouped_comments = array();
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        $group_id = $row["group_id"];
        $comment = $row["comment"];
        if (!isset($grouped_comments[$group_id])) {
            $grouped_comments[$group_id] = array();
        }
        $grouped_comments[$group_id][] = $comment;
    }
}

// 在每个分组中，使用PHP的字符串拼接功能将分组的注释添加到结果中
$output = "";
foreach ($grouped_comments as $group_id => $comments) {
    $output .= "<h2>Group " . $group_id . "</h2>";
    $output .= "<ul>";
    foreach ($comments as $comment) {
        $output .= "<li>" . $comment . "</li>";
    }
    $output .= "</ul>";
}

// 将所有结果返回给客户端，以便在Web页面上显示
echo $output;

// 关闭数据库连接
$conn->close();
?>