$(document).ready(funtion(){
    <?php
        $servername = "";
        $username = "";
        $password = "";

        $connection = new mysqli($servername, $username, $password);
        if ($connection->connect_error)
            die("Connection failed: ".$connection->connect_error);
        $sql = "SELECT nazwa from artysci";
        $result = $connection->query($sql);
        $result = array('1' => "jeden", '2' => "");
        $result = json_encode($result);
    ?>

    var wykonawcy = <?php json_encode($result); ?>;
    alert(wykonawcy);
});