php update mysql table via form, reload information on page immediately

Question

I'm creating a page in which room reservations are displayed in a table, with the possibilty to update or delete them.

The reservations come from a MySQL-database, table reservations.

It works, but I would like that the information from the database is updated on the page immediately after pressing the buttons.

For instance, if now I set the username from 'person' to 'another person', the field gets updated correctly in the database, but I need to refresch the page to see the update in my table.

How can I do this?

<table border="1">
<tr><td>Datum</td><td>Start</td><td>Stop</td><td>Gebruikersnaam</td></tr>

<?php
$now = date("Y-m-d");
$query = "SELECT * FROM reservations WHERE (roomid = " . 45 . " AND end > NOW() ) ORDER BY start"; 
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
$reservationid=$row["reservationid"];
$username=$row["username"];
$aantal=$row["numberingroup"];
$reservationid=$row["reservationid"];
$start=$row["start"];
$end=$row["end"];
$roomid=$row["roomid"];
?>

<form action="" method="post">
<tr><td><input name="StartDate" value="<? echo $StartDate; ?>" /></td><td><input name="StartTime" value="<? echo $StartTime; ?>" /></td><td><input name="StopTime" value="<? echo $StopTime; ?>" /></td><td><input name="username" value="<? echo $username;?>" /></td><td><input type="submit" value="update" name="<?php echo 'update_' . $reservationid; ?>" /></td><td><input type="submit" value="delete" name="<?php echo 'delete_' . $reservationid; ?>" /></td><td><? echo $reservationid; ?></td></tr></form>
<?php
//DELETE

if(isset($_POST['delete_' . $reservationid]))
{
$deletequery = "DELETE FROM reservations WHERE reservationid=" . $reservationid;
if(mysql_query($deletequery)){ 
echo "<p><b>Boeking verwijderd</b></p>";}
else {
echo "<p><b>Boeking niet verwijderd</b></p>";}
}

//UPDATE

if(isset($_POST['update_' . $reservationid]))
{
$NewStartDate = explode("-",$_POST[StartDate]);
$newstartdate = $NewStartDate[2] . "-" . $NewStartDate[1] . "-" . $NewStartDate[0];
$newstarttime = $_POST[StartTime] . ":00";

$newenddate = $newstartdate;
$NewEndTime = explode(":",$_POST[StopTime]);
$newendtime = mktime($NewEndTime[0],($NewEndTime[1]-1),59);
$newendtime = date("H:i:s",$newendtime);

$UpdateStart = $newstartdate . " " . $newstarttime;
$UpdateEnd = $newenddate . " " . $newendtime;

$UpdateUsername = $_POST[username];

$updatequery = "UPDATE reservations SET start='$UpdateStart', end='$UpdateEnd', username='$UpdateUsername' WHERE reservationid=" . $reservationid;
if(mysql_query($updatequery)){
echo "<p><b>Updated " . $reservationid . " " . $UpdateStart . " " . $UpdateEnd . " " .    $UpdateUsername . "</b></p>";}
else {
echo "<p><b>FAILURE IS NOT AN OPTION. AGAIN!</b></p>";}
}
?>

<?php
}
mysql_close();
?>

The working code is:

<?php
//DELETE

if(isset($_POST['delete_' . $_POST[updateid]]))
{
$deletequery = "DELETE FROM reservations WHERE reservationid=" . $_POST[updateid];
  if(mysql_query($deletequery)){
  echo "<p><b>Boeking verwijderd</b></p>";
  }
  else {
  echo "<p><b>FAILURE IS NOT AN OPTION. AGAIN!</b></p>";
  }
}

//UPDATE

if(isset($_POST['update_' . $_POST[updateid]]))
{
$UpdateID = $_POST[updateid];

$NewStartDate = explode("-",$_POST[StartDate]);
$newstartdate = $NewStartDate[2] . "-" . $NewStartDate[1] . "-" . $NewStartDate[0];
$newstarttime = $_POST[StartTime] . ":00";

$newenddate = $newstartdate;
$NewEndTime = explode(":",$_POST[StopTime]);
$newendtime = mktime($NewEndTime[0],($NewEndTime[1]-1),59);
$newendtime = date("H:i:s",$newendtime);

$UpdateStart = $newstartdate . " " . $newstarttime;
$UpdateEnd = $newenddate . " " . $newendtime;

$UpdateUsername = $_POST[username];

$updatequery = "UPDATE reservations SET start='$UpdateStart', end='$UpdateEnd', username='$UpdateUsername' WHERE reservationid='$UpdateID'";
  if(mysql_query($updatequery)){
  echo "<p><b>Updated " . $reservationid . " " . $UpdateStart . " " . $UpdateEnd . " " . $UpdateUsername . "</b></p>";
  }
  else {
  echo "<p><b>FAILURE IS NOT AN OPTION. AGAIN!</b></p>";
  }
//  echo "<p><b>Updated " . $reservationid . " " . $UpdateStart . " " . $UpdateEnd . " "  . $UpdateUsername . "</b></p>";
}
?>

<?php
$query = "SELECT * FROM reservations WHERE (roomid = " . 45 . " AND end > NOW() ) ORDER BY start"; 
$result = mysql_query($query) or die(mysql_error());
?>
<table border="1">
<tr><td>Datum</td><td>Start</td><td>Stop</td><td>Gebruikersnaam</td></tr>

<?php
while($row = mysql_fetch_array($result)){
$reservationid=$row["reservationid"];
$username=$row["username"];
$aantal=$row["numberingroup"];
$reservationid=$row["reservationid"];
$start=$row["start"];
$end=$row["end"];
$roomid=$row["roomid"];

$startdate = explode(" ",$start);
$startdate[0] = explode("-",$startdate[0]);
$startdate[1] = explode(":",$startdate[1]);
$StartFormat = mktime($startdate[1][0],$startdate[1][1],$startdate[1][2],$startdate[0][1],$startdate[0][2],$startdate[0][0]);
$StartDate = date("d-m-Y",$StartFormat);
$StartTime = date("H:i",$StartFormat);

$stopdate = explode(" ",$end);
$stopdate[0] = explode("-",$stopdate[0]);
$stopdate[1] = explode(":",$stopdate[1]);
$StopFormat = mktime($stopdate[1][0],$stopdate[1][1],($stopdate[1][2]+1),$stopdate[0][1],$stopdate[0][2],$stopdate[0][0]);
$StopDate = date("d-m-Y",$StopFormat);
$StopTime = date("H:i",$StopFormat);
?>
<form action="" method="post">
<tr><td><input type="hidden" name="updateid" value="<?php echo $reservationid; ?>" />    <input name="StartDate" value="<? echo $StartDate; ?>" /></td><td><input name="StartTime" value="<? echo $StartTime; ?>" /></td><td><input name="StopTime" value="<? echo $StopTime; ?>" /></td><td><input name="username" value="<? echo $username;?>" /></td><td><input type="submit" value="update" name="<?php echo 'update_' . $reservationid; ?>" /></td><td>  <input type="submit" value="delete" name="<?php echo 'delete_' . $reservationid; ?>" /></td> </tr>
</form>

<?php
}
mysql_close();
?>
</table>

Answer 1

Move the logic that does the updating and deleting above the logic that does the rendering:

<?php
// DELETE (your delete stuff)
// UPDATE (your update stuff)

// RETRIEVE (your SELECT query)
?>
<table> <!-- your table markup -->
<?php
// RENDER (your while loop and such)

You'll also need to adjust your logic a bit. You're using the $reservationid from the SELECT to do the deleting and updating. This doesn't work, because the execution context for the PHP is refreshed with each page load. What you need is to store the reservation id in each form (maybe in a hidden field), and then to retrieve that from $_POST .

Incidentally, your code is very vulnerable to SQL injection. Also, you should look at using mysqli or PDO ; mysql_connect is deprecated in the current version of PHP.

Answer 2

You could use jQuery for this. You have to make an $.ajax ( http://api.jquery.com/jquery.ajax/ ) call. From the callback you can fill/set the fields you want to. You'll need $('#idofelement').html() ( http://api.jquery.com/html/ ) for this. If you have got any questions don't be affraid to ask ;) Good luck!