PHP/mySQL - 如何将嵌套行提取到multidimensinal数组中

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

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

// 检查连接
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 执行查询
$sql = "SELECT id, name, age FROM users";
$result = $conn->query($sql);

// 初始化多维数组
$multiDimensionalArray = array();

// 使用循环将数据插入到多维数组中
if ($result->num_rows > 0) {
  while($row = $result->fetch_assoc()) {
    $multiDimensionalArray[] = $row;
  }
} else {
  echo "0 结果";
}

// 关闭数据库连接
$conn->close();

// 打印多维数组
print_r($multiDimensionalArray);
?>