如何在上传之前重命名文件（唯一名称）并在mysql数据库中保存路径[重复]

I am very new with PHP and facing great difficulty. Issue: 1. How to give a unique name to a file to be uploaded. 2. How to save the path in the database.

My code to upload file and save some information in database is:

<?php   
    $target = "images/";  $target = $target . basename( $_FILES['photo']['name']);   
    $name=$_POST['name'];  $email=$_POST['email'];  $phone=$_POST['phone'];  $pic=($_FILES['photo']['name']);   

    mysql_connect("localhost", "admin", "admin") or die(mysql_error()) ; 
    mysql_select_db ("database") or die(mysql_error()) ;   

    mysql_query("INSERT INTO `applicants` VALUES ('$name', '$email', '$phone', '$pic')") ;

    if(move_uploaded_file($_FILES['photo']['tmp_name'], $target))
    {   
        echo "Your application ". basename( $_FILES['uploadedfile']['name']). " has been uploaded, and your information has been saved";  
    }

    else {   
        echo "Sorry, there was a problem uploading your resume.";
    }
    ?>

Please help.

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The technique of generating a random number/string and then hashing that with a cheap algorithm is a good practice, but you need to check if that is indeed a unique value:

First generate a random something, and hash it using a cheap algorithm, eg.: md5

$filename = md5(rand() . substr(str_shuffle("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, 30) . rand());

Even though this seems totally random at first, MD5 is in fact has a not-so-great collision rate. Therefore, I suggest ensuring that this file does not exist yet. A cycle might be good for this case:

for ($i = 0; $i < 1000; $i++) {
    # Attempt to generate a unique filename
    $filename = md5(rand() . substr(str_shuffle("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, 30) . rand());

    # We don't have to keep trying if this file does not exist
    if (!file_exists("files/$filename.txt")) break;
}

Now you can proceed with whatever operations you want (eg.: inserting this path into a database).

1) There's a lot of different ways to give a file a unique name. You could generate a nasty looking guid http://php.net/manual/en/function.com-create-guid.php Or you could use something like this method as Daan mentioned: md5(microtime().date('d-m-Y H:i:s').$_FILES['file']['name']);

2) Just store the value of the path into a variable and use a simple sql insert to place it in the database. If you want more details you are going to need to post your code.