Undefined index [duplicate] - php

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Closed 10 years ago.
Possible Duplicate:
PHP: “Notice: Undefined variable” and “Notice: Undefined index”
hello everyone i am getting a problem while updating my record..when i click the edit button it doesnot update the record but give following errors to all post variables.. i would really appreciate any kind of comments or help...
this is courses-edit.php
<?php include("../includes/config.php"); ?>
<?php
if ($_SESSION["isteacher"])
{
$con=mysql_connect($dbserver,$dbusername,$dbpassword);
if (!$con) { die('Could not connect: ' . mysql_error()); }
mysql_select_db($dbname, $con);
$courseid=$_GET["id"];
$result = mysql_query("SELECT * FROM courses WHERE (id='".$courseid."')");
while($row = mysql_fetch_array($result))
{
$id=$row['id'];
$title = $row['title'];
$des = $row['description'];
$subjectid = $row['subjects-id'];
}
mysql_close($con);
?>
<script type="text/javascript">
$(function() {
$("form").validity(function() {
$("#title")
.require("This Field Must Be Filled!!")
});
});
</script>
<?php include("../includes/header.php"); ?>
<?php include("includes/nav.php"); ?>
<div id="maincontent">
<div class="span-24 last">
<div id="breadcrumbs">
Home >
Manage Courses >
List Courses >
Edit Course
</div>
</div>
<?php include("../teacher/includes/manage-courses-aside.php"); ?>
<div class="span-18 last">
<h2 class="alt">Edit Course</h2>
<form id="form" method="post" action="courses-edit-action.php">
<input type="hidden" value="<?php echo $courseid; ?>" name="id" />
<label>Course Name:</label><input type="text" name="title" id="title" class="text" value="<?php echo $title; ?>" /><br /><br />
<label>Choose Subject:</label>
<?php
$con=mysql_connect($dbserver,$dbusername,$dbpassword);
if (!$con) { die('Could not connect: ' . mysql_error()); }
mysql_select_db($dbname, $con);
$result = mysql_query("SELECT * FROM subjects");
echo "<select name='subjects-id'>\n";
while($row = mysql_fetch_array($result))
{
echo "<option value='".$row['id'] . "'";
if ($subjectid==$row['id'])
echo 'selected="selected"';
echo " >" . $row['subjectname'] . "</option>\n";
}
echo "</select>\n";
mysql_close($con);
?>
<label>Description:</label><textarea name="description" id="description"><?php echo $des; ?></textarea><br /> <br />
<input type="submit" value="Edit Course" class="button" />
</form>
<?php include("../includes/footer.php"); ?>
<?php
}
else
{
header("Location: ".$fullpath."login/unauthorized.php");
}
?>
and this is courses-edit-action.php
<?php include("../includes/config.php");?>
<?php
$id=$_POST["id"];
$title=$_POST["title"];
$des=$_POST["description"];
$subjectid=$_POST["subjects-id"];
$con=mysql_connect($dbserver,$dbusername,$dbpassword);
if (!$con) { die('Could not connect: ' . mysql_error()); }
mysql_select_db("ombts", $con);
$query=("UPDATE courses SET title='".$title."', description='".$des."', 'subjects- id'='".$subjectid."' WHERE (id='".$id."')");
$query=mysql_query($query);
if($result){
echo header("Location:manage-courses.php?status=2");
}
mysql_close($con);
?>
and the warnings are
Notice: Undefined index: id in C:\xampp\htdocs\project\teacher\courses-edit-action.php on line 4
Notice: Undefined index: title in C:\xampp\htdocs\project\teacher\courses-edit-action.php on line 5
Notice: Undefined index: description in C:\xampp\htdocs\project\teacher\courses-edit-action.php on line 6
Notice: Undefined index: subjects-id in C:\xampp\htdocs\project\teacher\courses-edit-action.php on line 7

Answer 1

You try to access
$id=$_POST["id"];
$title=$_POST["title"];
$des=$_POST["description"];
$subjectid=$_POST["subjects-id"];
this POST variables. But when you access the script for the first time this values are not set in the POST variable.
Chck the values with isset.
if(!isset($_POST["id"]) {
$_POST["id"] = '';
}
or safe the checked value in a new variable
$id = isset($_POST["id"]) ? $_POST["id"] : 0;
for example.

Answer 2

Modify your script like this....
$id= isset($_POST["id"]) ?$_POST["id"] : 0 ;
$title= isset($_POST["title"]) ? $_POST["title"] : '' ;
$des=isset($_POST["description"]) ? $_POST["description"] : '';
$subjectid= isset($_POST["subjects-id"]) ? $_POST["subjects-id"] : '';
Edited
Also, i see an error here...
$query=mysql_query($query);
if($result){
should be
$result=mysql_query($query);
if($result){
If you still can't update the table, print the $query variable before you do mysql_query. Tell me what you see and i will help you.....

Answer 3

#Stony's answer is good solution to check if you are sending any POST data - and if not, do not try to fetch non-existing data.
Now, if you think $_POST["id"]; should be there, then there is something missing. Are you using GET instead of POST?
To see what data is submitted do a print_r($_POST). If this is blank, do a print_r($_REQUEST). If this is still blank, then no data is being submitted from the previous page.
You can also check by adding this in your URL &id=75 (or ?id=75 if you have no other parameters in the url). This will submit data and you will see one less error.