How to query the database with php mysqli

<?php 
$code = $_POST[&#39;code&#39;];
$status = "";
$success = "";
$scookies = "";
try {
    $dbname="root";
    $dbpass="root";
    $dbhost="127.0.0.1";
    $dbdatabase="mysql";
 
    //生成一个连接
    $db_connect= new mysqli($dbhost,$dbname,$dbpass,$dbdatabase);
    // 获取查询结果
    $strsql="select * from `go_member_addmoney_record` where `code` = &#39;$code&#39; limit 1";
    $result=$db_connect->query($strsql);
    // 循环取出记录
    while ($row=mysqli_fetch_assoc($result))
    {
     $status = $row[&#39;status&#39;];
     $scookies = $row[&#39;scookies&#39;];
    }
    // 释放资源
    $result->close();
    // 关闭连接
    $db_connect->close();
    if($status=="已付款"){
        $success = "success";
    }
    else{
        $success = "faild";
    } 
    echo $success.";".$scookies;
}
catch (Exception $e){}