In this tutorial, we'll show how to establish a database connection to your MySQL database using PHP.

PHP and MySQL is one of the most common stacks for web development. With it such a common combination powering so many websites.

Database Connection settings

To be able to connect to a MySQL database, you need to update the following MySQL Database Connection Credentials.

Before that make sure to create a Database name, Database username​ and Password for your database user. 

Database Name, Database USER and Database Password can be created from your cPanel or from shell.​

DATABASE NAME, DATABASE USER, PASSWORD, HOSTNAME

Now, you've to create a sample.php file and copy the below code and replace the fields with your DATABASE Credentials. The below is how it looks in your terminal and the code follows.

================================================
<?php

//ENTER YOUR DATABASE CONNECTION INFO BELOW:

$hostname="localhost";
$database="test_db";
$username="test_user";
$password="qwe234@#$";

//DO NOT EDIT BELOW THIS LINE
$link = mysql_connect($hostname, $username, $password);
if (!$link) {
die('Connection failed: ' . mysql_error());
}
else{
echo "Host SUCCESS! " .$hostname . "
" . PHP_EOL;
}

$db_selected = mysql_select_db($database, $link);
if (!$db_selected) {
die ('Can't select database: ' . mysql_error());
}
else {
echo 'You have successfully established a connection to your DB ' . $database . '';
}

mysql_close($link);

?>
=============================================

Just RUN this sample.php files in your browser and you can see the below result on browser.

                                                                   http://IP/sample.php

Host SUCCESS! localhost You have successfully established a connection to your DB test_db

Conclusion

Finally, after complete reading this article you can surely connect your database using PHP.