PHP我的注册信息不是将数据发送到数据库

Question

我的代码不是将数据发送到数据库，但它让我有自己的错误，如数据库错误或其他什么。试过检查我的数据库它似乎是完美的。在post方法中，寄存器是按钮的名称

docker-1.13.1-22.gitb5e3294.fc26.x86_64

这是我的dbconnect，我已经对所有内容进行了双重检查，似乎我的代码中没有错误 dbconnect.php

<?php
        if(isset($_POST['register']))
        {
            @$username=$_POST['username'];
            @$password=$_POST['password'];
            @$cpassword=$_POST['cpassword'];
            @$role=$_POST['role'];

            if($password==$cpassword)
            {
                $query = "SELECT * FROM usersample WHERE username='$username'";
                //echo $query;
            $query_run = mysqli_query($con,$query);
            //echo mysql_num_rows($query_run);
            if($query_run)
                {
                    if(mysqli_num_rows($query_run)>0)
                    {
                        echo '<script type="text/javascript">alert("This Username Already exists.. Please try another username!")</script>';
                    }
                    else
                    {
                        $query = "INSERT INTO usersample(username,password,role)" ." values('$username','$password','$role')";
                        $query_run = mysqli_query($con,$query);
                        if($query_run)
                        {
                            echo '<script type="text/javascript">alert("User Registered.. Welcome")</script>';
                            $_SESSION['username'] = $username;
                            $_SESSION['password'] = $password;
                            header( "Location: index.php");
                        }
                        else
                        {
                            echo '<p class="bg-danger msg-block">Registration Unsuccessful due to server error. Please try later</p>';
                        }
                    }
                }
                else
                {
                    echo '<script type="text/javascript">alert("DB error")</script>';
                }
            }
            else
            {
                echo '<script type="text/javascript">alert("Password and Confirm Password do not match")</script>';
            }

        }
        else
        {
        }
    ?>