What does this undefined index message mean

Question

this code calls the values entered into a form and enters them into a database (or at least it's supposed to) every time the page loads it gives "undefined index" messages, and I am struggling to determine why.

Any help that can be offered to me is greatly appreciated!

<?php

$dbc=mysql_connect('localhost', 'user', '');
mysql_select_db('database', $dbc);



$sqlInsertString = "INSERT INTO band_information (Name, Photo, Bio, City, State, Zipcode, Genre, Link)
            VALUES ({$_POST['bandname']}, {$_FILES['bandphoto']['name']}, {$_POST['bandbio']}, {$_POST['bandcity']},
                    {$_POST['bandstate']}, {$_POST['bandzipcode']}, {$_POST['bandgenre']},{$_POST['bandlink']});";

if($_SERVER['REQUEST_METHOD']=='POST'){
    if(move_uploaded_file($_FILES['bandphoto']['tmp_name'], "C:\\HTML\\mgertenbach\\BAND\\photos\\{$_FILES['bandphoto']['name']}") && $mysql_query($sqlinsertString, $dbc)){
        print '<p>Thanks for submitting your band!</p>';
    } else {
        print '<p>Could not submit band because: <br/>' .
        mysql_error($dbc) . '</p>';
    }
}   

Answer 1

Since you are getting values from your <form> , you need to first check whether they are set or not.

You should make use of the isset construct for that. Like this

if(!isset($_POST['bandname'])) // And whichever variables you get from your <form>
{
echo "Band Name was not Provided";
exit;
}
else
{
//.... do your CRUD operations here
}

Secondly, you are using mysql_* functions which will be deprecated soon. Switch to MySQli or PDO instead.