根据设定价格和月份计算日期之间的价格[关闭]

Question

I am kind of stuck now and appreciate some help please. I have a Mysql table with 2 columns "month" and "price" i.e. January >> 5 (Euro); February >> 7 (Euro) and so on. On the booking form of the website the user can select arrival date and departure date. If the user selects a date with months in between, say 20.01.2013-12.04.2013, how can one calculate the full months (02 and 03) in between?

This is what i have got to calculate the days in arrival and departure months:

 ...
 $query="SELECT * FROM pricecal";
 $result=mysql_query($query);
 $num=mysql_numrows($result);

 $i=0;

 while ($i < $num)
  {

$month=mysql_result($result,$i,"month");
$price=mysql_result($result,$i,"price");

$i++;

$a = $_POST['dropToDay'];
$b = $_POST['dropToMonth'];
$c = $_POST['dropToYear'];
$d = $_POST['dropOffDay'];
$e = $_POST['dropOffMonth'];
$f = $_POST['dropOffYear'];

$days_to = (date('t',mktime(0, 0, 0, $a,(date($b) +1), date($c))) - $a +1);
$off_month_dif = (date('d-m-Y',mktime(0, 0, 0, $d,(date($e)), date($f))) - $d);
$days_off = (date('d-m-Y',mktime(0, 0, 0, $d,(date($e)), date($f))) - $off_month_dif);
$days = (date($f.$e.$d) - date($c.$b.$a));
$days_all = ($days+1);

if($b==$e AND $b==$month)
 {
  $b = $month;
  $pricing = $days_all*$price;
  echo 'Price for '.$days_all.' days is '.$pricing.' EUR.';
 }

if($b == $month AND $b != $e)
 {
  $pricing1 = $days_to*$price;
 }
if($e == $month AND $b != $e)
 {
  $pricing = $days_off*$price;
  $pricings_all = $pricing+$pricing1;
  echo 'Price for booking time: '.$pricings_all.' EUR';
 }
 .....

Answer 1

Build an array of month and prices (I am assuming that you are storing numeric months):

$price = array();
$query = "SELECT month, price FROM pricecal";
$result = mysql_query($query) or die(mysql_error()); 
while($row = mysql_fetch_assoc($result)) {
    $price[$result["month"]] = $result["price"];
}
// array(
// 1 => 5,
// 2 => 7,
// ...
// )

Next, build the two timestamps, loop through them and sum:

$ts1 = mktime(0, 0, 0, $_POST['dropToMonth'],  $_POST['dropToDay'],  $_POST['dropToYear']);
$ts2 = mktime(0, 0, 0, $_POST['dropOffMonth'], $_POST['dropOffDay'], $_POST['dropOffYear']);

for($ts = $ts1, $sum = 0; $ts <= $ts2; $ts = strtotime("+1 day", $ts)) {
    $sum += $price[date("n", $ts)];
}