Undefined index, error in my SQL?

I was trying to avoid posting this here as I wanted to work it out for myself. Anyway, after a few days, I am starting to lose motivation and really want to pass this hurdle so I can move on to the next.

I am making an app for tarantula keepers that helps keep track of feeds, molts, re-homes etc.

I'm trying to echo out all of the spiders in the database next to the username of the logged in user. I will work out how I can make it visually appealing once I have a working function. I tried it with the column spiderName first but can't get it working and for the life of me, I can't work out how.

Here's my function. Let me know if you need anything else:

function showSpiders(){
    global $connection;
    
    
    $username = $_SESSION['username'];
    $query = "SELECT * FROM userspiders WHERE username = '{$username}'";
    $result = mysqli_query($connection, $query);
    
    
    
        while($row = mysqli_fetch_row($result)){
        $spiderName = $row['SpiderName'];
            echo "$spiderName";
        
    }
}

What I have tried:

I have tried using "WHERE username LIKE" too, but no joy. I have also tried hard-coding the username variable.

Tags: SQL, PHP