php - 如何调试查询？

我正在尝试向mysql数据库中插入一些数据

$db = new DataBase($config);

// connect to the database RETURNS true if success false if fails
$conn = $db->connect();

// check whether the connection is successfull or not...
if ($db->isConnected())
     {

        //prepare the query
        $query = 'INSERT INTO scoreboard (score) VALUES(:score) WHERE username=:username';
        $bindings =  array(
                         'score'   =>  $score,
                        'username' => ($_SESSION['username'])

                         );


        // call the query function from db class and retrieve the results as an array of rows.
        $results = $db->setData($conn,$query,$bindings);
        if ($results)
            echo "Your Score is Updated!";
        else

            echo "Your Score is Not Updated!";


        }

这是setData（）的作用：

function setData($conn,$query,$bindings)
{
    try {

            // prepare the query
            $stmt = $conn->prepare($query);

            //binde the query with the data .here the data is $bindings
            $stmt->execute($bindings);

            return ( $stmt->rowCount() > 0 )
                // return the result if the query is success else return false.
                ? $stmt
                : false;
        }

        catch(Exception $e) {
            // return error if something goes wrong
            return false;
        }


}

每次运行此脚本时，都会得到“您的分数未更新”作为输出。

我要去哪里错了？

是$ _SESSION ['username']引起麻烦了吗？

任何有适当解释的帮助将不胜感激！

最佳答案

您要更新还是插入？在phpmyadmin上使用静态数据手动尝试查询，然后确保设置了会话并成功插入数据，则返回true