sql查询显示所有天数存在于数据库的两个日期之间

Tablename - Receipt

   coupondate    name      recno
   15-04-2015     A          1
   15-05-2015     A          1
   15-06-2015     A          1
   15-07-2015     A          1
   15-08-2015     A          1
   15-09-2015     A          1

FOR EX - Expected output

Days  15-04 16-04 17-04 18-04 19-04 20-04 21-04.....like wise upto 15-09
 A     P     P     P     P     P      P     P                        P

to display all days within selected date.

<?php
$startdate = $_POST['fromdate'];
$enddate = $_POST['todate'];
$start = date('d', strtotime($startdate));
$end=date('d', strtotime($enddate));
?>

<?php   for ($x = $start; $x <= $end; $x++) { ?>
    <th width="58%"><?php echo $x; ?></th>
<?php } ?>

below code to display P Else NULL

<?php if($row['coupondate'] == $x) { ?>
        <td>P</td>
        <?php }  else { ?>
        <td>NULL</td>

Now i cannot understand here how to display P if coupondate matched with $x date..

for ex - coupondate starts from 15-04 and end on 15-09 ok..

now i need to display P below to this customer from 15-04 upto 15-09