Updating dynamic links from database results - php

Question

I'm playing around with PHP a bit and am trying out dynamic links. My problem is that the corresponding ID is not correctly to the URL with my code, so I have the same link everytime.
Here is what I have:
<?php
$connection = mysqli_connect('localhost', 'root', 'password');
mysqli_select_db($connection, 'filme');
$query = "SELECT * FROM filme";
$result = mysqli_query($connection, $query);
$filmID = mysqli_fetch_assoc($result);
$array = array();
while($row = mysqli_fetch_assoc($result)){
$array[] = $row['Name'] . " - " . $row['Preis'];
}
$chunks = array_chunk($array, 4);
$filmID = mysqli_fetch_assoc($result);
echo "<table class='filme'>";
foreach ($chunks as $chunk){
echo '<tr>';
foreach ($chunk as $val) {
?><td><?php echo $val; ?> </td><?php
}
echo '</tr>';
}
echo "</table>";
mysql_close();
?>
What I'm trying to do is display a table with four columns, that in every cell has a string in the format of "Film name - Price" and this string should be a link that leads to the page with the according ID. This code does display my four column table, but it is missing the first item of my database and the ID is the same for every link, namely the ID of that first film that is missing. So every URL looks like this:
http://localhost/dvd.php?Film_ID=1000
But the film with the ID 1000 is not even listed. I thought about putting that nested foreach loop in a while loop with
while($filmID = mysqli_fetch_assoc($result)){
...
}
But with that I get a blank page.
I have just about no experience with php, so sorry if I'm missing something really obvious.

Answer 1

You are going about this the wrong way. There's no link here between the contents of $array and $filmID. Indeed, $filmID is probably empty because you've already run through your result set earlier. Imagine your database result set is like a stack of papers. Each call to fetchAssoc() reads one sheet of paper, and sets it aside. Once you reach the end of the result set, there's nothing left to read, so your next calls will fail. You need to do all your database fetch in a single loop. As well, you should not be using mysql_close() with mysqli.
<?php
$connection = mysqli_connect('localhost', 'root', 'password');
$connection->select_db('filme');
$query = "SELECT * FROM filme";
$result = $connection->query($query);
$array = array();
while($row = mysqli_fetch_assoc($result)){
$array[] = $row;
}
$chunks = array_chunk($array, 4);
echo "<table class='filme'>";
foreach ($chunks as $chunk){
echo '<tr>';
foreach ($chunk as $film) {
?><td><?php echo "$film[Name] - $film[Preis]"; ?> </td><?php
}
echo '</tr>';
}
echo "</table>";
mysqli_close();
Or, better yet, just use the more modern PDO library:
<?php
$connection = new PDO("mysql:host=localhost;dbname=filme", "root", "password");
$query = "SELECT `Film_ID`, `Name`, `Preis` FROM filme";
$result = $connection->query($query);
$chunks = array_chunk($result->fetchAll(PDO::FETCH_ASSOC), 4);
?>
<table class='filme'>
<?php foreach ($chunks as $chunk):?>
<tr>
<?php foreach ($chunk as $film):?>
<td>
<?=htmlspecialchars("$film[Name] - $film[Preis]")?>
</td>
<?php endforeach?>
</tr>
<?php endforeach?>
</table>
Note this code is much more efficient and easier to read due to use of alternative syntax and short echo tags to keep PHP and HTML mixing to a minimum. Ideally your PHP would be in a totally separate file.