PHP - MySql数据库信息不存储

Question

I have been trying to figure this out for hours, I have created a database ( MySql/PHPMyadmin) and i am trying to get user input stored to be able to call back up, however the info is not making it/ saving it to the database, everything shows up okay except this part of code:

$registered = mysqli_affected_rows ($dbc);

        echo $registered. "Row is affected";

when run gives me a display of -1 row, I believe this to be a big part of the problem as everything else seems to work okay. I am a complete beginner so could you guys tell me how the best way of debugging this is.

$dbc = $dbc = mysqli_connect ($hostname, $username, $password, $dbname) OR die("Could not Connect");

To input the data to the db i have the following:

if ($_SERVER['REQUEST_METHOD'] == 'POST'){

        $comments = $_POST ['Comments'];

        if (!empty ($comments)){

        include ('mysqldb.php');

        mysqli_query ($dbc,"INSERT INTO 'User-Comments' (Comments) VALUES ('$comments')");

        $registered = mysqli_affected_rows ($dbc);

            echo $registered. "Row is affected";

        }else {
                echo "Nothing Submitted";
            }

        }

Answer 1

An excerpt from the documentation for function mysqli_stmt_affected_rows(): -1 indicates that the query has returned an error.

You should check the value returned by mysqli_query(). If it returns FALSE then you can get details about the reason (error message) by using function mysqli_error().