How to dynamically populate new page with variable set on last page? - php

Question

I'm new to PHP and am trying to build my a website to display information on TV shows stored in a MySQL DB. I've currently got a webpage that will create a table to display the information in the DB, however I'd like each row to link to a dynamically populated page with more info on each show (also pulling from the DB). My question is how do I get the site to know which link has been clicked and then save that as a variable so it can then be recalled on a new to populate the correct information?
I'm currently using this to populate the page.
<!--Populate page with data from SQL-->
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "media_server";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT show_title, show_desc, thumbnail_path FROM tv_shows WHERE status = 'Y'";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
echo "<table><tr><th></th><th></th></tr>";
// output data of each row
while($row = $result->fetch_assoc()) {
echo "
<tr>
<td>
<img src='../images/thumbnails/tv/".$row["thumbnail_path"]."'>
</td>
<td class='td_title'>
<a href='#' onclick='show_var_set();'>".$row["show_title"]."</a>
</td>
<td class='td_desc'>".$row["show_desc"]."</td>
</tr>";
}
echo "</table>";
} else {
echo "Error - 0 results were returned my the database. Please try again.";
}
$conn->close();
?>

Answer 1

One option is to change your href links to point to this page and pass a GET variable you can retreive. The added bonus to this approach is you could bookmark a particular show and come back to that page, since the bookmark will include that GET variable.
So you could change your links to something like this:
echo '', $row['show_title'],'';
Then you'd retrieve that variable by testing for, then reading the GET variable and performing a db query to populate the page with that show's data.
Here's how you'd test for and retreive that variable:
if (isset($_GET['show']))
{
$show = $_GET['show'];
// Perform database lookup using $show
}
Remember to never put user input directly into a query, but use prepared statements and bind the user data to avoid the risk of SQL injection.

Answer 2

There are many ways to pass values from page to page but one is to use session variables:
//Include this at the top of your php scripts that use session variables
session_start();
$_SESSION['your_variable_name_here'] = value_you_want_to_store;
Then on the page you would like to access this use:
$someVariable = $_SESSION['your_variable_name_here'];

Answer 3

Change the SQL to return the show_id,
$sql = "SELECT show_id, show_title, show_desc, thumbnail_path FROM tv_shows WHERE status = 'Y'";
and use that as a parameter to the show_var_set() function.
<a href='#' onclick='show_var_set(".$row["show_id"].");'>".$row["show_title"]."</a>
The show_var_set() function can then use that parameter to get the details for that show from the database.