Código PHP:
$sql = "SELECT u.*, s.*
FROM " . SESSIONS_TABLE . " s, " . USERS_TABLE . " u
WHERE s.session_id = '$session_id'
AND u.user_id = s.session_user_id";
if ( !($result = $db->sql_query($sql)) )
{
message_die(CRITICAL_ERROR, 'Error doing DB query userdata row fetch', '', __LINE__, __FILE__, $sql);
}
. 
