MySQL link to return results - php

Question

I have an image that is displayed from a table and I want the user to be able to click the image which directs them to a page that returns the rest of the data for that row. Do I need a php loop for this? I can't quite figure it out.
This returns the Last Name, First Name, and an Image:
<?php
if (isset($_GET['LastName'])) {
$ln = $_GET['LastName'];
}
include 'connection.php';
$query = "SELECT * FROM residents WHERE LastName like '$ln%' ";
$result = mysql_query($query);
while($person = mysql_fetch_array($result)) { ?>
<div class="media col-sm-4">
<a class="pull-left" href="redirectionpage.php?<?php echo $person['ID'];?>.php">
<img class="media-object" src="upload/<?php echo $person['Picture'];?>" width="100" height="100"/>
</a>
<div class="media-body">
<h4 class="media-heading"><?php echo $person['LastName'] . ", " . $person['FirstName']; ?></h4>
</div>
</div>
<?php }>?
Is the best way to accomplish this by redirecting the user to a new page and using a mysql statement to display the new data?
This is the code for the other page:
<?php
//Gets data from the database
include ('header.php');
include ('footer.php');
include ('connection.php');
$query = "SELECT * FROM residents WHERE ID = LastName LIMIT 1";
$result = mysql_query($query);
while($row = mysql_fetch_array($result)){
$outputpicture.='<div><p><img src="upload/' . $row['Picture'].'" width="450" height="550"/></p></div>';
$outputname.= $row['LastName'] . ", " . $row['FirstName']. '<br />';
$outputspouse.= $row['Spouse']. '<br />';
$outputrelatives.= $row['Relatives']. '<br />';
$outputaddress.= $row['Address']. '<br />';
$outputbirthday.= $row['Birthday']. '<br />';
$outputbegan.= $row['BeganResidence']. '<br />';
$outputended.= $row['EndedResidence']. '<br />';
$outputformer.= $row['FormerResidence']. '<br />';
$outputcareer.= $row['Career']. '<br />';
$outputeducation.= $row['Education']. '<br />';
$outputmaritalstatus.= $row['MaritalStatus']. '<br />';
$outputsiblings.= $row['Siblings']. '<br />';
$outputspecialinterests.= $row['SpecialInterests'].'<br />';
}
?>

Answer 1

The link needs to be changed to
<a class="pull-left" href="redirectionpage.php?id=<?php echo $person['ID'];?>">
Adding this id= will allow you to access the id parameter in redirectionpage.php via the $_GET superglobal.
$id = $_GET['id'];
You can use the $id variable to select the specified row from your database. You will see a lot of examples that do it like this:
$query = "SELECT * FROM residents WHERE ID = $id";
This works but you should not do it, because it creates an SQL injection vulnerability. Read about prepared statements and create your SQL so that you can pass the ID as a paramater.
$stmt = $pdo->prepare("SELECT * FROM residents WHERE ID = :id");
$stmt->bindValue(':id', $id, PDO::PARAM_INT);
$stmt->execute();
This should also be applied to the code you use to select the list of images.
Assuming ID is the key for your residents table, this should select only one record, so you will not need the while loop. You can just use one fetch.