从输入创建每个用户的唯一文件夹，并使用php保存该文件夹中的图像

I'm working on project for creating Online Exam for college Entrance. I am looking for solution to upload image and create folder using user serial id as which is as per mysql database primary increment idsave the images inside the folder.

Here is my solution where images are uploaded in already created folder called uploads. How to modify this for what I required.

<?php
session_start();
include('../connect.php');
$a = $_POST['name'];

// query

$file_name  = strtolower($_FILES['file']['name']);
$file_ext = substr($file_name, strrpos($file_name, '.'));
$prefix = 'your_site_name_'.md5(time()*rand(1, 9999));
$file_name_new = $prefix.$file_ext;
$path = '../uploads/'.$file_name_new;


    /* check if the file uploaded successfully */
    if(@move_uploaded_file($_FILES['file']['tmp_name'], $path)) {

  //do your write to the database filename and other details   
$sql = "INSERT INTO student (name,file) VALUES (:a,:h)";
$q = $db->prepare($sql);
$q->execute(array(':a'=>$a,':h'=>$file_name_new));
header("location: students.php");

    }
?>

</div>

First: Be careful uploading files without correctly checking it's types;

Second: As Sean mentioned, this approach may get out of control.

--

The following example changed the steps that you tried.

First insert the user to get it's ID and then create the folder under '../uploads' with it.

This way you do not need to move the file two times (move the file to ../uploads, insert the user and then move the file again to ../uploads/userID)

<?php

...

$sql = "INSERT INTO student (name,file) VALUES (:a,:h)";
$q = $db->prepare($sql);
$q->execute(array(':a'=>$a,':h'=>$file_name_new));

// Get user id
$studentId = $db->lastInsertId();

// Create path with new userId just inserted
$path = "../uploads/$studentId/";
if(!file_exists($path)) { // maybe  "&& !is_dir($path)" ?
   // IMPORTANT NOTE: the second argument is the permission of the folder. 0777 is the default and may cause security flaws
   mkdir($path, 0777, true);
}

// Move the uploaded file to new path with the userId
@move_uploaded_file($_FILES['file']['tmp_name'], $path.$file_name_new);

I think you need to check if the user already exists before inserting (but I don't know the details of your project)