DB Type: MariaDB
Table Engine: InnoDB

I have a table where inside it has a column with a value which is being incremented (not auto, no inserting happens in this table)

When I run the following SQL query in phpMyAdmin it works just fine as it should:

UPDATE `my_table` 
    SET `my_column` = LAST_INSERT_ID(`my_column` + 1) 
WHERE `my_column2` = 'abc'; 
SELECT LAST_INSERT_ID();

The above returns me the last value for the my_column table when the query happened. This query was taken directly from the mysql docs on locking: https://dev.mysql.com/doc/refman/8.0/en/innodb-locking-reads.html (to the bottom) and this seems to be the recommended way of working with counters when you don't want it to be affected by other connections.

My PDO:

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            
    $sql = "UPDATE `my_table` 
                SET `my_column` = LAST_INSERT_ID(`my_column` + 1) 
                WHERE `my_column2` = 'abc'; 
            SELECT LAST_INSERT_ID();";

    // Prepare statement
    $stmt = $conn->prepare($sql);

    // execute the query
    $stmt->execute();

    $result = $stmt->fetchColumn(); // causes general error
    $result = $stmt->fetch(PDO::FETCH_ASSOC);// causes general error

    // echo a message to say the UPDATE succeeded
    echo $stmt->rowCount() . " records UPDATED successfully";
        
} catch(PDOException $e) {            
    echo $sql . "<br>" . $e->getMessage();        
}
$conn = null;

Exact error SQLSTATE[HY000]: General error, If I remove the lines where I try to get the result, it updates the column, but I still do not have a return result... how do I perform that update query and get the select result all in one go like I do when I run it in phpMyAdmin? This all needs to happen in one go as specified by the MySQL docs so I don't have issues where two connections might get the same counter.