<?php
  $result=$db->query("SELECT id,examples,nexamples FROM sessions ORDER BY id");
  $SESSIONS_next = -1;
  while ($session = $result->fetch(PDO::FETCH_ASSOC)) {
    $SESSIONS[$session['id']] = array("id" => $session['id'], "timestr" => date("d.m.Y H:i", $session['id']),
      "workdone" => $db->query("SELECT COUNT(*) FROM workdone WHERE session=" . $session['id'])->fetch(PDO::FETCH_NUM)[0],
      "examples" => $session['examples'], "nexamples" => $session['nexamples']);
    if ( strtotime("now") < $session['id'] && ( $SESSIONS_next==-1 || $SESSIONS_next > $session['id'] )  ) {
      $SESSIONS_next = $session['id'];
    }
  }
  if($SESSIONS_next == -1) unset($SESSIONS_next);

  $SESSIONS_totex = 0;
  foreach ($SESSIONS as $session) {
    if($session['id'] < $SESSIONS_next) { $SESSIONS_totex += $session['nexamples']; }
  }
?>