Chap. 6 - delete.php

BozHogan · January 30th, 2010, 08:28 PM

Two questions:

The code in the example handles the Cascade Delete if you delete the lead actor, but seems to omit the case of deleting a director? Don't we need to do the same thing if the user tries to delete a director?

Secondly, when we update the movie_leadactor field to '0', is that going to cause problems, since there is no one in the people table with an id of 0?

TIA,
Boz

Luachan · February 19th, 2010, 10:43 AM

Hi all, guys.

I have a problem with the page delete.php: when I try to delete the movie "Test", I see this error:

Quote:

Notice: Undefined index: do in C:\Programmi\EasyPHP5.3.0\www\film\delete.php on line 5
Are you sure you want to delete this movie?
yesor no

This is the delete.php code:

PHP Code:


			
<?php

    $db = mysql_connect('localhost', 'bp6am', 'bp6ampass') or die ('Unable to connect');

    mysql_select_db('moviesite', $db) or die (mysql_error($db));

    

    if(isset($_GET['do']) || $_GET['do'] != 1) {

        switch ($_GET['type']) {

            case 'movie':

                echo 'Are you sure you want to delete this movie?<br />';

                break;

            case 'people':

                echo 'Are you sure you want to delete this person?<br />';

                break;

            }

            echo '<a href="' . $_SERVER['REQUEST_URI'] . '&do=1">yes</a>';

            echo 'or <a href="admin.php">no</a>';

        }

    else

        {

            switch ($_GET['type']) {

                case 'people':

                    $query = 'UPDATE movie SET

                            movie_leadactor = 0

                        WHERE

                            movie_leadactor = ' . $_GET['id'];

                    $result = mysql_query($query, $db) or die(mysql_error($db));

                    

                    $query = 'DELETE FROM people

                            WHERE

                                people_id = ' . $_GET['id'];

                    $result = mysql_query($query, $db) or die(mysql_error($db));

?>

<p style="text-align: center;">Your person has been deleted. <a href="movie_index.php">Return to Index</a></p>

<?php

                    break;

                case 'movie':

                    $query = 'DELETE FROM movie                                

                            WHERE

                                movie_id = ' . $_GET['id'];

                    $result = mysql_query($query, $db) or die(mysql_error($db));

?>

<p style="text-align: center;">Your movie has been deleted. <a href="movie_index.php">Return to index</a>

<?php

                break;

            }

        }

?>

It seems that 'do' is not defined. How can I solve this?
Thanks

BozHogan · February 19th, 2010, 03:51 PM

You're right. the first time through 'do' is not defined and shouldn't be.

You have a mistake in the code on line 5. You need to add an "!" before the isset function, thus:

Code:

if(!isset($_GET['do']) || $_GET['do'] != 1) {

What's happens with an "OR" condition is that the first expression gets evaluated, if it's true, the "OR" is satisfied and it doesn't even look at the second condition. If it's false, it looks at the second one to see if IT is true. That's what is happening here. It's looking at $_GET['do'] != 1 and causing the error.

Your code is asking first if the 'do' is set. Since it isn't, it evaluates to false and looks at the second condition which is where your error occurs.

What needs to happen is the first condition needs to ask if the 'do' is NOT set. Since it isn't, this evaluates to TRUE, the "OR" is satisfied and it never bothers to look at the $_GET['do'] != 1 part, so no errors.

In short, just add that ! to "NOT OUT" the isset, and you should be fine.

Regards, and welcome to the forum!
Boz

Luachan · February 22nd, 2010, 09:47 AM

Thanks a lot, Boz!

I meet several errors in the scripts and I don't know why. For example:

Quote:

Notice: Undefined index: action in C:\Programmi\EasyPHP5.3.0\www\film\movie.php on line 5
Movie Name
Movie Type
Movie Year
Lead Actor
Director

Notice: Undefined index: action in C:\Programmi\EasyPHP5.3.0\www\film\movie.php on line 141

and this is the code of movie.php:

PHP Code:


			
<?php

    $db = mysql_connect('localhost', 'bp6am', 'bp6ampass') or die ('Unable to connect');

    mysql_select_db('moviesite', $db) or die (mysql_error($db));

    

    if ($_GET['action'] == 'edit') {

        //recuperare le informazioni del record

        $query = 'SELECT

                movie_name, movie_type, movie_year, movie_leadactor, movie_director

            FROM

                movie

            WHERE

                movie_id = '. $_GET['id'];

        $result = mysql_query($query, $db) or die (mysql_error($db));

        extract(mysql_fetch_assoc($result));

        } else {

            //azzera i valori

            $movie_name = '';

            $movie_type = 0;

            $movie_year = date('Y');

            $movie_leadactor = 0;

            $movie_director = 0;

        }

                

?>

<html>

    <head>

        <title><?php echo ucfirst($_GET['action']); ?> Movie</title>

    </head>

<body>

    <form action="commit.php?action=<?php echo $_GET['action']; ?>&type=movie" method="post">

        <table>

            <tr>

                <td>Movie Name</td>

                <td><input type="text" name="movie_name" value="<?php echo $movie_name; ?>" /></td>

            </tr>

            <tr>

                <td>Movie Type</td>

                <td>

                    <select name="movie_type">

                        <?php

                            //seleziona il tipo di film

                            $query = 'SELECT

                                    movietype_id, movietype_label

                                FROM 

                                    movietype

                                ORDER BY

                                    movietype_label';

                            $result = mysql_query($query, $db) or die (mysql_error($db));

                            

                            //popola le opzioni della select con i risultati

                            while ($row = mysql_fetch_assoc($result)) {

                                foreach ($row as $value) {

                                    if ($row['$movietype_id'] == $movie_type) {

                                        echo '<option value="' . $row['$movietype_id'] . '" selected="selected">';

                                    } else {

                                    echo '<option value="' . $row['movietype_id'] . '">';

                                    }

                                    echo $row['movietype_label'] . '</option>';

                            }

                        }

                        ?>

                    </select>

                </td>

            </tr>

            <tr>

                <td>Movie Year</td>

                <td><select name="movie_year">

                    <?php

                        //popola le opzioni della select con gli anni

                        for  ($yr = date("Y"); $yr >= 1970 and $yr <= 2020; $yr++) {

                            echo '<option value="' . $yr . '">' . $yr . '</option>';

                        }

                    ?>

                    </select>

                </td>

            </tr>

            <tr>

                <td>Lead Actor</td>

                <td><select name="movie_leadactor">

                    <?php

                        //seleziona i record degli attori

                        $query = 'SELECT

                                people_id, people_fullname

                            FROM

                                people

                            WHERE

                                people_isactor = 1

                            ORDER BY

                                people_fullname';

                        $result = mysql_query($query, $db) or die (mysql_error($db));

                        

                        //popola le opzioni della select con i risultati

                        while ($row = mysql_fetch_assoc($result)) {

                            foreach ($row as $value) {

                                    if ($row['$people_id'] == $movie_leadactor) {

                                        echo '<option value="' . $row['$people_id'] . '" selected="selected">';

                                    } else {

                                echo '<option value="' . $row['people_id'] . '">';

                                }

                                echo $row['people_fullname'] . '</option>';

                        }

                    }

                    ?>

                    </select>

                </td>

            </tr>

            <tr>

                <td>Director</td>

                <td>

                    <select name="movie_director">

                    <?php

                        //seleziona i record dei registi

                        $query = 'SELECT

                                people_id, people_fullname

                            FROM

                                people

                            WHERE

                                people_isdirector = 1

                            ORDER BY

                                people_fullname';

                        $result = mysql_query($query, $db) or die (mysql_error($db));

                        

                        //popola le opzioni della select con i risultati

                        while ($row = mysql_fetch_assoc($result)) {

                            foreach ($row as $value) {

                                    if ($row['$people_id'] == $movie_director) {

                                        echo '<option value="' . $row['$people_id'] . '" selected="selected">';

                                    } else {

                                echo '<option value="' . $row['people_id'] . '">';

                                }

                                echo $row['people_fullname'] . '</option>';

                        }

                    }

                    ?>

                    </select>

                </td>

            </tr>

            <tr>

                <td colspan="2" style="text-align: center;">

                <?php

                    if ($_GET['action'] == 'edit') {

                        echo '<input type="hidden" value="' . $_GET['id'] . '" name="movie_id" />';

                        }

                ?>

                    <input type="submit" name="submit" value="<?php echo ucfirst ($_GET['action']); ?>" />

                </td>

            </tr>

        </table>

    </form>

</body>

</html>

BozHogan · February 22nd, 2010, 01:13 PM

I don't see a problem in your script. I think it's probably in your admin.php file. movie.php is expecting to be called like this:

movie.php?action=edit&type=movie

This call puts information in the $_GET array. You can see it when you hover your mouse over the link.

Look for the lines in admin.php that contain:

href="movie.php?action=

My guess is that one of them has action spelled incorrectly. If not, just post the code for admin.php and I'll have a look.

Also check out the post I started with "Tip: echo vs print". I posted some code and at the bottom there are some lines you can put at the end of movie.php that display the contents of the $_GET and $_POST arrays. I use this to keep track of what my programs are passing back and forth to each other. Hope this helps.

Boz

hozdaman · September 27th, 2010, 04:38 PM

Hi I'm having a similar error with this example. Everytime I run the script and click delete all I get is "yes or no" and nothing else. Please help. THanks.

PHP Code:


			
<?php 
if (!isset($_GET['do']) || $_GET['do'] !=1) {
    switch ($_GET['type'])  {
    case 'movie':
        echo 'Are you sure you want to delete this movie?<br/>';
        break;
    case 'people':
        echo 'Are you sure you want to delete this person?<br/>';
        break;
    }
    echo '<a href="' . $_SERVER['REQUEST_URI'] . '&do=1">yes</a> ';
    echo 'or <a href="admin.php">no</a>';
} else {
    switch ($_GET['type']) {
    case 'people':
        $query = 'UPDATE movie SET
                movie_leadactor=0
            WHERE
                movie_leadactor = ' . $_GET['id'];
        $results = mysql_query($query) or die(mysql_error());

        $query = 'DELETE FROM people
            WHERE
                people_id= ' . $_GET['id'];
        $results = mysql_query($query) or die(mysql_error());
?>

<p style="text-align:center;">Your person has been deleted.
<a href="movie_index.php">Return to index</a></p>

<?php
        break;
    case 'movie':
        $query = 'DELETE FROM movie
            WHERE
                movie_id = ' . $GET['id'];
        $results = mysql_query($query) or die(mysql_error());
?>

<p style="text-align: center;">Your movie has been deleted.
<a href="movie_index.php">Return to index</a></p>

<?php
        break;
    }
}
?>