PHPにおけるmysqli_query関数の役割

mysqli_query(connection,query,resultmode);

<?php 
// 假定数据库用户名：root，密码：123456，数据库：RUNOOB 
$con=mysqli_connect("localhost","root","123456","RUNOOB"); 
if (mysqli_connect_errno($con)) 
{ 
    echo "连接 MySQL 失败: " . mysqli_connect_error(); 
} 
 
// 执行查询
mysqli_query($con,"SELECT * FROM websites");
mysqli_query($con,"INSERT INTO websites (name, url, alexa, country)
VALUES (&#39;百度&#39;,&#39;https://www.baidu.com/&#39;,&#39;4&#39;,&#39;CN&#39;)");
 
mysqli_close($con);
?>