Mysql Dates / PHP - php

Question

I am working on a calendar in PHP. With the calendar, I am able to query a mysql database and it will show the number of events for each day. The problem I'm having is that it is showing the start and end dates but i need it to also show all the days inbetween.Thus, showing that the days inbetween are also occupied. My current Table has DepDate (departure) AND RetDate (Return Date). Im thinking this has to be done through the mysql query. Any help would be awesome! Thanks buds
<script>
function goLastMonth(month, year, keyname){
if(month == 1) {
--year;
month = 13;
}
--month
var monthstring= ""+month+"";
var monthlength = monthstring.length;
var keyname = "<?php echo $searchTerm; ?>";
if(monthlength <=1){
monthstring = "0" + monthstring;
}
document.location.href ="<?php $_SERVER['PHP_SELF'];?>?month="+monthstring+"&year="+year+"&keyname="+keyname;
}
function goNextMonth(month, year, keyname){
if(month == 12) {
++year;
month = 0;
}
++month
var monthstring= ""+month+"";
var monthlength = monthstring.length;
var keyname = "<?php echo $searchTerm; ?>";
if(monthlength <=1){
monthstring = "0" + monthstring;
}
document.location.href ="<?php $_SERVER['PHP_SELF'];?>?month="+monthstring+"&year="+year+"&keyname="+keyname;
}
</script>
</head>
<?php
if (isset($_GET['day'])){
$day = $_GET['day'];
} else {
$day = date("j");
}
if(isset($_GET['month'])){
$month = $_GET['month'];
} else {
$month = date("n");
}
if(isset($_GET['year'])){
$year = $_GET['year'];
}else{
$year = date("Y");
}
$currentTimeStamp = strtotime( "$year-$month-01");
$monthName = date("F", $currentTimeStamp);
$numDays = date("t", $currentTimeStamp);
$currentTimeStamp = strtotime( "$day-$month-$year"); // added this to reset this value for prev* and next* code
$counter = 0;
?>
<?php
include ('plane.css');
/* ------------------------------------------------------------Calendar Creation---------------------------------------------------------------------- */
include ('planeh.html');
?>
<?php
//get previous month
$prevMonth = $month - 1;
$prevYear = $year;
if($prevMonth <= 0){
$prevMonth = 12;
$prevYear--;
}
$pMonthStr = "" + $prevMonth;
if(strlen($pMonthStr) <= 1)
$pMonthStr = "0" + $pMonthStr;
//get num of day for previous month
$previousTimeStamp = strtotime( "01-$pMonthStr-$prevYear");
$prevNumDays = date("t", $previousTimeStamp);
$numDays = date("t", $currentTimeStamp);
$counter = 0;
for($i = 1; $i < $numDays+1; $i++, $counter++){
$timeStamp = strtotime("$year-$month-$i");
if($i == 1) {
$firstDay = date("w", $timeStamp);
for($j = 0; $j < $firstDay; $j++, $counter++) {
$prevDay = $prevNumDays-$firstDay+$j+1;
echo "<td class = td3><div id = prev>$prevDay</div></td>";
}
}
if($counter % 7 == 0) {
echo"</tr><big></big><tr>";
}
/* Up to this point, everything is the development of the calendar */
$monthstring = $month;
$monthlength = strlen($monthstring);
$daystring = $i;
$daylength = strlen($i);
if($daylength <=0){
$daystring = "0".$daystring;
}
// links and date located on calendar
$todaysDate = date("m/d/y");
/* Indicates date located on calendar */
echo "<td align = center class = td3><div class = button>".$i."</a></div>";
$sqlEvent2 = mysql_query("select * FROM trips where DepDate = '".$year."-".$month."-".$i."'");
$num_rows = mysql_num_rows($sqlEvent2);
if(mysql_errno()){
echo "MySQL error ".mysql_errno().": "
.mysql_error()."\n<br>When executing <br>\n$query\n<br>";
}
echo '<div id="button">';
echo "<a href='".$_SERVER['PHP_SELF']."?month=".$monthstring."&day=".$i."&year=".$year."&v=true' >".$num_rows."</a></td>";
echo '</div>';
}
echo "<tr>";
echo"</table>";
?>
<div id ="menu">
<?php include ('menu2.php');?>
</ul>
</div>
</div>
</tr>
</body>
</html>

Answer 1

All you need here is to reference the MySQL date and time functions, specifically datediff: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_datediff
An example would be:
SELECT start_dt, end_dt, datediff(end_dt, start_dt) as days_elapsed
FROM my_table
where start_dt and end_dt are both date valued.