Get all images from this database table

This is my code. Where I’m wrong?

<?php
    $connection = mysql_connect($DB_HOST, $DB_USER, $DB_PASSWORD); 
    mysql_select_db($DB_NAME);
    $img = mysql_query("SELECT * FROM wp_bwg_image");

    while($res = mysql_fetch_array($img)){
        echo $res;
    }
?>

From this table I want to take any pictures.