mysql server port number

If your MySQL server runs on default settings, you don't need to specify that.

Default MySQL port is 3306.

[updated to show mysql_error() usage]

$conn = mysql_connect($dbhost, $dbuser, $dbpass)
    or die('Error connecting to mysql: '.mysql_error());

For windows, If you want to know the port number of your local host on which Mysql is running you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'port';


mysql> SHOW VARIABLES WHERE Variable_name = 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.00 sec)

It will give you the port number on which MySQL is running.