PHP文件上传，重命名文件名

Question

Main goal is to upload files with a unique file_name every time. This file will sit on our webserver and the file_path will be mapped to our database. Then it will be displayed on a post from the file path stored in the database.

I am using the code from here ( http://www.w3schools.com/php/php_file_upload.asp )

I need to rename the files that are being uploaded to a auto incremental integer. So the first file uploaded will be 1.file_extention , then the next will be 2.file_extention , and so...

What is the best way to do this?

Answer 1

If you are really set on using incremental numbers (probably not the best way) and you will be mapping these files in the db anyway, why not do the db insert first (I'm assuming your table has an auto-increment id field) and then use the id field from the row you inserted as the name of the file?

The caveat is that, if renaming the file using the id from the db fails for some reason, you'll need to remove that row but, any time you use such a mapping, you'll need to take that kind of care.

Answer 2

Hi you can prefix time stamp using below method

<?php
$target_dir = "uploads/";
$target_file = $target_dir . time().basename($_FILES["fileToUpload"]["name"]); // NOTICE THAT I CONCORDINATED TIME STAMP BEFORE THE FILE NAME
$uploadOk = 1;
$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}
?>

If you want to concordinate the primary key you have to insert the record first then to upload the file. If file not uploaded then you have to throw a warning to user that the image not uploaded or have to delete the record.

<?php
    require 'dbConnection.php';

    $stmt = "INSERT INTO TABLENAME (id, name, created) VALUES (NULL, '$name', NOW())";
    $qry = mysql_query($stmt);

    $lastInsertedId = mysql_insert_id();


    $target_dir = "uploads/";
    $target_file = $target_dir . $lastInsertedId.'_'.basename($_FILES["fileToUpload"]["name"]); // NOTICE THAT I CONCORDINATED TIME STAMP BEFORE THE FILE NAME
    $uploadOk = 1;
    $imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
    // Check if image file is a actual image or fake image
    if(isset($_POST["submit"])) {
        $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
        if($check !== false) {
            echo "File is an image - " . $check["mime"] . ".";
            $uploadOk = 1;
        } else {
            echo "File is not an image.";
            $uploadOk = 0;
        }
    }

?>

If you are using PDO connection then you have to modify slightly.