PHP undefined index - sortby

Question

Its basically displaying data from mysql database and using

$sortby = $_GET['sort'];

And the error I get is

Notice: Undefined index: sort in /home/4507408/public_html/list.php on line 8

Here is the full code, any ideas? (Line 8 is $sortby = $_GET['sort'];)

Thanks for looking :)

<?php
$dbhost = 'localhost';
$dbuser = 'CU4507408';
$dbpass = 'adamadam1';
$dbname = 'CU4507408';
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die("Error connecting to        database");
mysql_select_db($dbname);
$sortby = $_GET['sort'];
?>

Thats at the top of the page

<table border="1">

    <tr>
        <th><a href="list.php?sort=name">Product Name:</a></th>
        <th><a href="list.php?sort=price">Price £</a></th>
        <th><a href="list.php?sort=manufacturer">Manufacturer</a></th>
        <th><a href="list.php?sort=rating">Rating</a></th>
        <th><a href="list.php?sort=categoryname">Category</a></th>
    </tr>
    <?php
    $query = "SELECT p.productID, p.name, p.price, p.manufacturer, p.rating, c.categoryname FROM product p INNER JOIN category c WHERE p.categoryID=c.categoryID ORDER BY $sortby ASC;";
    $result = mysql_query($query) or die("failed!");
    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
        ?>
        <tr>

            <td><a href="link.php?productID=<?= $row['productID'] ?>"><?= $row['name'] ?></a></td>
            <td><?= $row['price'] ?></td>
            <td><?= $row['manufacturer'] ?></td>
            <td><?= $row['rating'] ?></td>
            <td><?= $row['categoryname'] ?></td>
        </tr>
<? } ?>

mysql extension is deprecated, instead use mysqli or PDO_MySQL . — Muhammad
– Muhammad, Commented Jan 10, 2014 at 12:13
Where do you get the sort from? Seems to be not send or defined properly there. Do an echo $_REQUEST to see how that looks like. ;) — loveNoHate
– loveNoHate, Commented Jan 10, 2014 at 12:13
When you load page, sort is not defined and this is what spits error. Do check and create default value. As suggested by hsz. — user796443
– user796443, Commented Jan 10, 2014 at 12:14

hsz · Accepted Answer · 2014-01-10 12:12:36Z

5

Just try with:

$sortby = isset($_GET['sort']) ? $_GET['sort'] : 'default_value';

Also if you use valriables passed with $_GET you have to check if it is not a value that inject something in your query. Good practise is to:

$sortbyValues = array('price', 'manufacturer', 'rating', 'categoryname');
$sortby = isset($_GET['sort']) && in_array($sortby, $sortbyValues) ? $_GET['sort'] : 'default_value';

answered Jan 10, 2014 at 12:12

hsz

153k63 gold badges268 silver badges320 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

hsz Over a year ago

@user3181679 If you find my answer correct, remember to accept it with the tick on the left.

Adam91Holt Over a year ago

I will do, you answered it that fast that I can't yet haha! I will tho :)

Dinesh Saini · Accepted Answer · 2014-01-10 12:18:45Z

1

Problem is occurs because your index is not set on configuration file. You can use any of the following options:

 @$sortby = $_GET['sort'];

 $sortby = isset($_GET['sort']) ? $_GET['sort'] : 'default_value';

answered Jan 10, 2014 at 12:18

Dinesh Saini

2,9162 gold badges36 silver badges50 bronze badges

3 Comments

hsz Over a year ago

Did you copy my answer ? ;-)

Dinesh Saini Over a year ago

I have give both options to use still I can mention your credit there :)

hsz Over a year ago

However using @ is not a good practice. You should avoid errors/notices instead of ignoring them.

marc_s · Accepted Answer · 2019-04-19 20:29:39Z

0

Remove this line from your code

 $sortby = $_GET['sort'];

Add this code in top of your code

 if (isset($_GET['sort']) && !empty($_GET['sort'])) {
        $sortby = $_GET['sort']; 
    }else{  
       /*in case value of $_GET['sort'] is not retrieved, Action can be done for error handling here. */
    }

edited Apr 19, 2019 at 20:29

marc_s

760k186 gold badges1.4k silver badges1.5k bronze badges

answered Jan 10, 2014 at 12:22

vivek

3261 gold badge4 silver badges15 bronze badges

1 Comment

vivek Over a year ago

because of we can define other value if GET is empty

Collectives™ on Stack Overflow

PHP undefined index - sortby

3 Answers 3

2 Comments

3 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related