PHP automatically chooses to connect to the local database or remote database

Suppose we want to test. when operating the VM database in the PHP file, you must first debug it locally. Therefore, you must connect to two different databases locally and remotely. question: how to make test. does php automatically identify whether to connect to a local database or a remote database? Mysql. class. php file see http://www.jb51.net/article/25496.htm

The code is as follows:

// Contains the Mysql operation class
Include_once 'MySQL. class. php ';
// Local mysql data
$ Mysql_local_data = array ('Db _ host' => 'localhost ',
'Db _ user' => 'root ',
'Db _ pass' => 'root ',
'Db _ name' => 'test ');
// Remote mysql data
$ Mysql_remote_data = array ('Db _ host' => '61. 183.41.178 ',
'Db _ user' => 'XXX ',
'Db _ pass' => 'XXX ',
'Db _ name' => 'XXX ');
// Public data
$ Tb_prefix = 'php95 _';
$ Db_charset = 'utf-8 ';
// If the local connection is successful, the local Mysql class is instantiated. Otherwise, the local database is connected and the Mysql class is instantiated.
If (@ mysql_connect ($ mysql_local_data [db_host], $ mysql_local_data [db_user], $ mysql_local_data [db_pass])
$ Db = new Mysql ($ db_host, $ mysql_local_data [db_user], $ mysql_local_data [db_pass], $ mysql_local_data [db_name], $ db_charset, $ conn );
Else
$ Db = new Mysql ($ mysql_remote_data [db_host], $ mysql_remote_data [db_user], $ response [db_pass], $ mysql_remote_data [db_name], $ db_charset, $ conn );
$ Db-> show_tables (); // test: displays the names of all tables in the current database.
?>