Question regarding hashing the database connection password

Hi,

I have a question regarding hashing the database connection password.

Right now I connect to the database via PDO. I have a file.ini that will go outside of root with the database credentials. Everything in the ini file is in plaintext right now.

//config.ini db credentials

servername = "localhost"
user = "admin_test"
pass = "treehouse"
dbname = "db_test"

//Retrieve credentials
$config = parse_ini_file("config.ini");

$this->servername = $config['servername'];
$this->dbname = $config['dbname'];
$this->user = $config['user'];
$this->pass = $config['pass'];

//connect to the database
...

Am I supposed to hash the database password or something? My mind is going in circles right now and I can't figure it out. If I hash the plaintext pass then I need to verify it before connecting, but I don't have the key to verify the hash against since leaving any trace of the password in your code is bad practice.

I realize leaving plaintext passwords in your tables is a big no-no in case the database gets hacked. But what about the actual database password? Can I do something about this except leaving the config file outside of root? I'm not really sure how the mysql database handles/stores its own admin password since it's not in a visible table like you would treat any users of your site.

I would love a security class on treehouse. I find this topic really difficult to grasp.

thanks!