如何从数据库中获取单个数据

I am building a web-based database collection for the company I work for. The marketing department needs an app where they can add and also retrieve data about clients.

I am just a networking guy who wants to be useful

This is for developers who use Linux and have idea about php and mysql.

<?php
$query = "SELECT * FROM star";
$shouts = mysqli_query ($route, $query);
?>



<?php while($row = mysqli_fetch_assoc($shouts)) : ?>
 <p> <?php echo $row['respond'] ?> </p>
<?php endwhile;?>

I have succeed in fetching data i need from the database, but there is a respond column that i want to fetch the data in it into a pop up modal box, i want it to appear according to the id of row. Like when i click on entry one, the response that will appear should be that of entry one ID