[RESOLVED] PHP $_GET issues

mpar612

Hello everyone,

I am new to the forums and new to PHP. I'm not sure if this is out of scope for this forum, because it also entails a little bit of SQL. If this is out of scope, please let me know.

Here is a bit of my code:

$isbn = $GET['isbn'];
if ($POST['submit_check']) {
if ($POST['yes_no'] == 'yes') {
$delete_sql = "DELETE FROM lounge WHERE isbn = $isbn";
$db->query($delete_sql);
print "Entry deleted";
} elseif ($_POST['yes_no'] == 'no') {
print 'Entry not deleted';
}
} else {
print "Cannot process form";
}

I am trying to delete a record from a MySQL database. I am getting some information from the url: www.domain.com/delete.php?isbn=123 and use that isbn=123 as part of the SQL statement. I can print the $GET['isbn'] on the screen and it works. The SQL query works in phpmyadmin when I use isbn = 123, but it won't work when I assign the $GET['isbn'] to a variable named $isbn. I think I am having some problems putting these two things together. I can post more code if needed.

Any feedback would be greatly appreciated. Thanks in advance!!!

TheDefender

Change to:

$delete_sql = "DELETE FROM lounge WHERE isbn = '$isbn'";

mpar612

Thanks! I tried that and the code appeared to execute, but when I checked the database in phpmyadmin it did not delete the entry. I did not get any errors or anything.

I just realized that I forgot to mention that this is an INT in the MySQL database.

harmor

If you haven't changed the field from INT to varchar you can change the value of the field for "yes_no" to 1 or 0

<input type="radio" name="yes_no" value="1" />Yes
<input type="radio" name="yes_no" value="0" />No

$isbn = $_GET['isbn'];
if ($_POST['_submit_check']) 
{
	 if ($_POST['yes_no'] == '1') 
	{
		$delete_sql = "DELETE FROM lounge WHERE isbn = $isbn";
		$db->query($delete_sql);
		print "Entry deleted";
	} 
	elseif ($_POST['yes_no'] == '0') 
	{
	     print 'Entry not deleted';
	}
} 
else 
{
   print "Cannot process form";
}

Sorry but I can't stand the format you used. It's harder to read the code the way you had it.

mpar612

Thank you! I used your code and I received the following error: "DB Error: syntax error". However, if I add single quotes around the $isbn in the DELETE query, the code appears to execute, but nothing is deleted from the database.

May I ask what is hard to understand about my coding? I'm new and any tips would be great.

Thank you for your help.

mpar612

Hi everyone,

I have narrowed this down a bit more. I apologize if some of this is a restatement from what I posted previously.

I have narrowed this down to one more level.

This code works fine by itself in between the <?php and ?> tags:

$isbn = $_GET['isbn'];
$sql = "DELETE FROM lounge WHERE isbn = $isbn";
$db->query($sql);
print $sql;

The code does not work and gives me a "DB Error: syntax error" when I place it inside of an if statement like this:

if ($_POST['yes_no'] == 'yes') {

$isbn = $_GET['isbn'];
$sql = "DELETE FROM lounge WHERE isbn = $isbn";
$db->query($sql);
print $sql;
} else {
print "Record not deleted";
}

Is this common? Does anyone know why this won't work?

Thanks!

mpar612

Just in case anyone else stumbles across this, using $GET and $POST at the same time makes things a little more difficult. That's what my issue was.

I ended up adding a hidden field in my form and assigning the $GET value to the value of the hidden field. From there I could pull the information that I wanted to use with $GET using $_POST and my SQL query executed perfectly.

I was extremely baffled with this problem when I found this forum and was not sure how to resolve this, that's why I made my post. After searching through this forum I was able to find the answers to my problems and solved it myself. There is a ton of great information in these forums.

Thanks for all of your help!