I wrote support ssl mysqli you don't need change anymore mysqli connect exchange to your own mysqli . Overwrite __construct mysqli with support ssl can be like that: 
<?php class myssl_mysqli extends \mysqli {
        public function __construct($db_host, $db_user, $db_pass, $db_name, $port, $persistent = true, $ssl = false, $certpublic = "") {
            if($ssl) {
        parent::init();
                parent::options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, false);
        parent::ssl_set(NULL, NULL, $certpublic, NULL, NULL);
            parent::real_connect(($persistent ? 'p:' : '') . $db_host, $db_user, $db_pass, $db_name, $port, '', MYSQLI_CLIENT_SSL | MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT );
            } else {
                 parent::__construct($db_host, $db_user, $db_pass, $db_name, $port);
            }
}
$db = new myssl_mysqli('localhost','user', 'pass','db', '3306', true, true, '/home/mypublicowncert.pem'); 
?>
in this example i off the verificate cert by authority ssl, due it own cery created

Correct way to connect db 

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("127.0.0.1", "db_user", "db_pass", "db_name",3306);

$result = $mysqli->query("SELECT somefield1, somefield2 FROM sometable ORDER BY ID LIMIT 3");

/* Close the connection as soon as it becomes unnecessary */
$mysqli->close();

foreach ($result as $row) {
    /* Processing data received from the database */
echo var_dump ($row);
}