Shortcode, Concatenating & Parse error: syntax error, unexpected T_FOREACH

I'm learning how to write a shortcode. I'm getting this error: Parse error: syntax error, unexpected T_FOREACH . I'm having problems with concatenating it properly.

<?php
/*
Plugin Name:  My Plugin
Plugin URI: http://mysite.com
Description: This does blah
Version: 1.0
Author URI: http://www.mysite.com
*/




function csf_cap_databaseinfo() {
    global $wpdb;



    $greeting = $wpdb->get_results($wpdb->prepare("SELECT * FROM wp_test;")); 

     $out = '<table>
               <tr>
             <th>ID</th>
                 <th>Greeting</th>
               </tr>'; 

      $out .=  foreach ($greeting as $greet){ .'<tr><td>' . echo $greet->id . '</td></tr>' . } .'</table>'; 

        return $out; 

}


add_shortcode('db-info', 'csf_cap_databaseinfo');
?>

Any suggestion on how to fix this error? Thank you.

-Laxmidi