Open Shift Mysql data connection using php - php

Question

I am fresher for Open shift.
Here is my problem in Open shift.
I completed creating application with php, Mysql and PhpMyAdmin
Then I went to phpMyAdmin and created a new database 'Students_list'
Now I am unable to connect to my database with the following code in php pages.
$db_host = $_ENV['127.12.123.2']; //sample host
$db_user = $_ENV['adminnxUpXA6'];
$db_pass = $_ENV['lyPfbtHYpDFcU'];
$db_name = $_ENV['students_list']; //this is the database I created in PhpMyAdmin
$db = new mysqli($db_host, $db_user, $db_pass);
if ($db->connect_errno) {
die('Connect Error (' . $db->connect_errno . ') '
. $db->connect_error);
}
mysqli_select_db($db,$db_name);
May I please know where I am comitting the error.

Answer 1

Try this instead:
$db_host = getenv('OPENSHIFT_MYSQL_DB_HOST'); //sample host
$db_user = getenv('OPENSHIFT_MYSQL_DB_USERNAME');
$db_pass = getenv('OPENSHIFT_MYSQL_DB_PASSWORD');
$db_name = 'students_list'; //this is the database I created in PhpMyAdmin
$db = new mysqli($db_host, $db_user, $db_pass);
if ($db->connect_errno) {
die('Connect Error (' . $db->connect_errno . ') '
. $db->connect_error);
}
mysqli_select_db($db,$db_name);

Answer 2

You are using $_ENV, which contains environment variables from the operating system. Most probably what you wanted to do is this:
$db_host = 'ip';
$db_user = 'username';
$db_pass = 'password';
$db_name = 'students_list';

Answer 3

The structure for the mysqli connection string is this:
mysqli(Hostname,Username,Password,DatabaseName);