Deleting MySQL data Help.

[Joshua Kidd]

Hey Guys,
I need some help with Deleting data from a MySQL .

Currently I have, Two PHP files.
the First is the main page.

<?php 
$host="";
$username="";
$password="";
$db_name="";
$tbl_name="";

mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

$sql="SELECT * FROM $tbl_name";
$result=mysql_query($sql);
?>
<p>This Page Refreshes Every 10 Seconds</p>
<table width="500" border="0" cellspacing="1" cellpadding="0">
<tr>
<td><table width="200%" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td colspan="7" bgcolor="#FFFFFF"><strong>Current Flight Plans using the GVA Flight Planner</strong> </td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFFF"><strong>ID</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Username</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Tail Number</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Departure Airport</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Destination Airport</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>IFR or VFR</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Cruising Altitude</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Remarks</strong></td>
<td align="center" bgcolor="#FFFFFF">&nbsp;</td>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
?>
<tr>
<td bgcolor="#FFFFFF"><center><? echo $rows['ID']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['Username']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['TailNumber']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['DepartureAirport']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['DestinationAirport']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['IFRorVFR']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['CrustingAltitude']; ?></center></td>
<td bgcolor="#FFFFFF"><center><? echo $rows['Remarks']; ?></center></td>
<td bgcolor="#FFFFFF"><center><a href="delete_ac.php?id=<? echo $rows['id']; ?>">delete</a></center></td>
</tr>
<?

// close while loop 
}

// close connection; 
mysql_close();

?> 
</table></td>
</tr>
</table>

And then I have my Delete_ac.php page with this

<?php

$host="";
$username="";
$password="";
$db_name="";
$tbl_name="";

mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

$id=$_GET['id'];

$sql="DELETE FROM $tbl_name WHERE id='$id'";
$result=mysql_query($sql);

if($result){
echo "Deleted Successfully";
echo "<BR>";
echo "<a href='Administrator.php'>Back to main page</a>";
}

else {
echo "ERROR";
}

mysql_close();

?>

And now My problem is when I click Delete on the Main page, it says it Deleted it Successfully but When I go back to the Main Page it still Shows the row the I clicked Delete on.
Can someone Please help me on why this is Happening? Thanks in Advance :)

[vibhaJ]

Code is looking w/o error.
can you check $tbl_name variable in both page.

[Joshua Kidd]

The table name Variable in Both Pages is the Same so no Error there.

[diafol]

is this for admin only?

<? echo $rows['id']; ?>

you're using sort tags - do you see the id value in the querystring (url)?

this not v. secure - if anybody guesses the name of your page, they'll cause havoc. protect all deletes with login check and possibly a confirmation hash.

[Joshua Kidd]

Yes It is For Administrators only, will be getting to the Password Protection soon.
Yeah, When I click Delete it does show something more than the ID value:
URL Looks like this
delete_ac.php?id=<br%20/><b>Notice</b>:%20%20Undefined%20index:%20id%20in%20<b>C:\xampp\htdocs\Flight%20Planner\Administrator.php</b>%20on%20line%20<b>52</b><br%20/>
But Im not sure If that is the ID or what.

[diafol]

Nope, that's an error.

[Joshua Kidd]

It says line 52, and my line 52 in the Administrator.php page is

<td bgcolor="#FFFFFF"><center><a href="delete_ac.php?id=<? echo $rows['id']; ?>">delete</a></center></td>

But I dont see why there would be an error there, Maybe should I use something other than

<a href="delete_ac.php?id=<? echo $rows['id']; ?>">delete</a>

?

[diafol]

<? echo $rows['id']; ?>

did you change this to:

<?php echo $rows['id']; ?>

as I mentioned previously?

[Joshua Kidd]

I Did change that to

<?php echo $rows['id']; ?>

But It is Still giving me this Error in the URL. The same one too, pointing to Line 52 Again. Nothing Different.

[diafol]

OK, prob not a short tag issue, but you;ve also got a short tag here:

<?
 
// close while loop 
}
 
// close connection; 
mysql_close();
 
?>

So essentially what you have is:

<?php
$sql="SELECT * FROM $tbl_name";
$result=mysql_query($sql);
...
while($rows=mysql_fetch_array($result)){
...
?>
<a href="delete_ac.php?id=<?php echo $rows['id']; ?>">delete</a>
...
<?php
...
}
?>

1. Does the 'id' field exist or is it called something else in the DB?
2. if it exists, are there any records? check with mysql_num_rows()
3. If all OK. Echo out the sql statement and see if it makes sense, and then run it in phpMySQL or the GUI of your choice. Does it work as expected / return what you thought?

[karthik_ppts]

Just use this code to test your sql statement is correct.

echo $sql="DELETE FROM $tbl_name WHERE id='$id'";
$result=mysql_query($sql);