关闭先前打开的数据库连接：
<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// ....一些 PHP 代码...
mysqli_close($con);
?>
关闭先前打开的数据库连接：
<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// ....一些 PHP 代码...
mysqli_close($con);
?>