如何利用mysqli_query函数执行SQL查询

<?php
// 创建数据库连接
$connection = mysqli_connect("localhost", "用户名", "密码", "数据库名");
 
// 检查连接是否成功
if (!$connection) {
  die("数据库连接失败：" . mysqli_connect_error());
}
 
// 执行查询语句
$result = mysqli_query($connection, "SELECT * FROM users");
 
// 遍历查询结果
while ($row = mysqli_fetch_assoc($result)) {
  echo "ID：" . $row["id"] . "，姓名：" . $row["name"] . "，年龄：" . $row["age"] . "<br>";
}
 
// 关闭数据库连接
mysqli_close($connection);
?>