<?php
function dstats2_idFromRewriting() {
   global $tableposts, $wpdb;

   $fuvarstoreset = array('year', 'monthnum', 'day', 'name' );
   ## see $wpvarstoreset in wp-blog.header.php

   for ($i=0; $i<count($fuvarstoreset); $i += 1) {
      $wpvar = $fuvarstoreset[$i];
      if (!isset($$wpvar)) {
         if (empty($_POST[$wpvar])) {
            if (empty($_GET[$wpvar]) && empty($path_info[$wpvar])) {
               $$wpvar = '';
            } elseif (!empty($_GET[$wpvar])) {
               $$wpvar = $_GET[$wpvar];
            } else {
               $$wpvar = $path_info[$wpvar];
            }
         } else {
            $$wpvar = $_POST[$wpvar];
         }
      }
   }
   if ('' != $year) {
      $year = '' . intval($year);
      $where .= " AND YEAR(post_date)='$year'";
   }
   if ('' != $monthnum) {
      $monthnum = '' . intval($monthnum);
      $where .= " AND MONTH(post_date)='$monthnum'";
   }
   if ('' != $day) {
      $day = '' . intval($day);
      $where .= " AND DAYOFMONTH(post_date)='$day'";
   }
   if ('' != $name) {
      $name = preg_replace('/[^a-z0-9-_]/', '', $name);
      $where .= " AND post_name = '$name'";
   }

   $request = " SELECT ID FROM $tableposts WHERE 1=1".$where;
      ## the 'WHERE 1=1'-trick: no error when $where==''...
   $fuposts = $wpdb->get_results($request);

   if(count($fuposts)>1){
      # more than one post => something went wrong
      return '0';
   }else{
      return $fuposts[0]->ID;
   }
}
?>