I have made this class for database connections to my applications. It eases out the task of making connections to the database with knowing the credentials in advance and provides a way to execute the queries.Class dbConnection {    public $CONN;    private $dbservername, $dbusername, $dbpassword, $dbname;    public function __construct() {        $this->dbservername = localhost;        $this->dbusername = dbroot;        $this->dbpassword = pass;        $this->dbname = test;        $this->open(); //open the connection on instantization    }    public function open() {    // Create connection        $this->CONN = new mysqli($this->dbservername, $this->dbusername, $this->dbpassword, $this->dbname);        // Check connection        if ($this->CONN->connect_error) {            die(Connection failed:  . $CONN->connect_error);        }    }    public function prepare($query) {    //prepare the data        return $this->CONN->prepare($query);    }    public function close() {    //close the connection        $this->CONN->close();    }}I am using prepared statements in the queries, of course.I would like a review to determine if the function is feasible in all situations with performance and security on top considerations. I want to know if I should make any adjustments to it. Also, a comment on the coding style would be of great use.
Class for database connections in PHP
php;object oriented;mysqli