PHP - 查询错误

Question

我正在尝试使用mysqli_query，但我的查询似乎有问题而且我不知道在哪里。

  

adminhostelryadd.php

    <?php 

    include '../connection/connect.php';

    $adminhostelryform = json_decode(file_get_contents("php://input"));

    $data = array();

    $emptyform = false;
    $validateusername = false;
    $usernamelength = false;
    $passwordlength = false;
    $querysuccess = false;

    $hostelryqueryname = $adminhostelryform->hostelryname;
    $hostelryquerytype = $adminhostelryform->hostelrytype;
    $hostelryquerydescription = $adminhostelryform->hostelrydescription;
    $hostelryqueryusername = $adminhostelryform->hostelryusername;
    $hostelryquerypassword = $adminhostelryform->hostelrypassword;

    if(isset($hostelryqueryname) && isset($hostelryquerytype) && isset($hostelryquerydescription) && isset($hostelryqueryusername) && isset($hostelryquerypassword)) {

        if(empty($hostelryqueryname) && empty($hostelryquerytype) && empty($hostelryquerydescription) && empty($hostelryqueryusername) && empty($hostelryquerypassword)) {
            $emptyform = true;

        } else {

            $checkusername = mysqli_query($conn, "SELECT hostelry_username FROM hostelryacc WHERE hostelry_username='$hostelryqueryname'");
            $validate = mysqli_num_rows($checkusername);
            if($validate) {
                $validateusername = true;
            } else {

                if(strlen($hostelryqueryusername) < 5) {
                    $usernamelength = true;
                } else if(strlen($hostelryquerypassword) < 5) {
                    $passwordlength = true;
                } else {
                    $id = "ADMINHOSTELRY-" . rand(10, 100) . "-" . rand();
                    $query = mysqli_query($conn, "INSERT INTO hostelryacc VALUES('$id', '$hostelryqueryname', '$hostelryquerytype', '$hostelryquerydescription', '$hostelryqueryusername', '$hostelryquerypassword')");

                    if($query) {
                        $querysuccess = false;
                    } else {
                        $querysuccess = true;
                    }

                }

            }

        }

    }

    $data["emptyform"] = $emptyform;
    $data["validateusername"] = $validateusername;
    $data["usernamelength"] = $usernamelength;
    $data["passwordlength"] = $passwordlength;
    $data["querysuccess"] = $querysuccess;

    echo json_encode($data);


 ?>

  

我的$ query = mysqli_query出现了问题（$ conn，＆＃34; INSERT INTO   hostelryacc VALUES（＆＃39; $ id＆＃39;，＆＃39; $ hostelryqueryname＆＃39;，＆＃39; $ hostelryquerytype＆＃39;，   ＆＃39; $ hostelryquerydescription＆＃39;，＆＃39; $ hostelryqueryusername＆＃39;，   ＆＃39; $ hostelryquerypassword＆＃39;）＆＃34）;