Making a connection between PHP and MySQL database

Firstly, I create a page called connection.php and input some code:

$connection => a string to be called for the connection. This string can be stated by any name such as db, connection,...

mysql_connect() requires a host name, user name and password (in that order).

Add a die() function to the mysql_connect() line to cause the script to end and a message to display if the connection fails.
Within the die() function, use the mysql_error() function in order to print out the exact error sent by MySQL.

the full code will be input like this:


However, the connection error is shown:



the error cause the problem is mysql_connect function. It lacks of @ so we can fix like



the problem still happen:



This error mean I use wrong user name and pass in order to connect to MySQL Database server.

Other method to connect

Creating 4 variables such as :

// This is to connect to localhost server, it can be domain name hoặc IP address
$SERVER = " localhost";

//account user name which logins MySQL server, is root
$USERNAME = " root";

//account password to login mysql server
$PASSWORD="";

With MySQL syntax:

mysql_connect($server_address, $username, $password)

I have some lines of code :