Display sql query result (from textarea input) into a table without knowing the number of columns

It starts off with the user having to input their query from a textarea.

<div class="querybar">
        <div class="form-item">
            <form action="" method="POST" class="simple-form">
            <textarea id="sqlquery" name="sqlquery" rows="3" cols="120" placeholder="Type your query here"></textarea>
        </div>
        <div class="form-item">
            <input type="submit" name="submit" value="Submit">
            </form>
        </div>
    </div>

and then it should display the result of the query–if its a select statement–into a table regardless of the number of columns
(example: I have productlist table which has 4 columns, and orders table with 8 columns, and it should be able to display all columns whether I query for ‘productlist’ or ‘orders’)
otherwise it just displays a success message

if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['submit']))
{                 
        $sql = $_POST['sqlquery'];
        $trimmedSQL = trim($sql);
        
        if(!empty($trimmedSQL)) 
        {  
            $stmt = $db-> prepare($trimmedSQL);
            $stmt = execute();
            $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);

            if ( strstr( strtoupper($trimmedSQL), 'SELECT' ) )
            {
                //print all the results into a table
            } 
            else
            {
                echo "<div class = 'success-msg'><div><i class='fa-solid fa-circle-check'></i><b> Success!</b> Processed SQL query.</div></div>";
            }
        }
        else
        {
                echo "No query!";
        }
}

what should I place in place of the comment, for this to happen? or is it completely wrong?
I’m sorry if this may sound like its already been answered before, but the answer I found didn’t seem to work for my case.