Want to store and retrive data in MySQL on different pages - php

Question

I'm handling a project and from long time that project is in the middle. The problem is : to store and retrive contents from MySQL database (locally in WAMP Server).
The brief overview about the project which inculdes the folowing steps:
1) Users can create account,
2) Upload files (whcih can be text(.rtf & .txt), images (.jpg & .png ), docs (.doc, .xls, .pptx, .pdf ) & videos (.avi & .mp4 ))
3) View those files and
4) Modify them.
So the concept is :
1) User logs-in or do sign-up,
2) He gets options the following options : Text, Images, Docs & Videos.
3) The user choose any option : which opens a new page where user can view his/her existing content in Thumbnail view with its name and
4) There's an option on top of everything to "Add new". Here we've two conditions:
If user clicks on existing, user can view it and delete the existing files. For example, if it's a video, user can play it by clicking on thumbnail.
If user clicks on "Add new", it takes user to another page where user can upload the respective content.
So, the problem is that no one in my team (we're in college, not in a company) knows the queries to store the file into database & after uploading it, retrieve the file's name and thumbnail (only in case of image & video otherwise, a default thumbnail) on previous page.
One of my team member tried to do it, but the uploaded file is shown in every user's account.
So I want to know how we can do it. I mean to say, specific programming code for both problems.
P.S.: If possible please let me know how to set restrictions(validations) of file choosing (like during uploading FB cover, it shows only IMAGES not ALL FILES).

Answer 1

This should help you. But be sure to clean this code from sql injections.
//This is the directory where images will be saved
$target = "pics/";
$target = $target . basename( $_FILES['Filename']['name']);
//This gets all the other information from the form
$Filename=basename( $_FILES['Filename']['name']);
$Description=$_POST['Description'];
//Writes the Filename to the server
if(move_uploaded_file($_FILES['Filename']['tmp_name'], $target)) {
//Tells you if its all ok
echo "The file ". basename( $_FILES['Filename']['name']). " has been uploaded, and your information has been added to the directory";
// Connects to your Database
mysql_connect("localhost", "root", "") or die(mysql_error()) ;
mysql_select_db("yourdbname") or die(mysql_error()) ;
//Writes the information to the database
mysql_query("INSERT INTO tbl_files (Filename,Description)
VALUES ('$Filename', '$Description')") ;
} else {
//Gives and error if its not
echo "Sorry, there was a problem uploading your file.";
}

Answer 2

// Connect to your Database
mysql_connect("localhost", "root", "") or die(mysql_error()) ;
mysql_select_db("dbname") or die(mysql_error()) ;
// directory where images will be moved
$file=mktime()."_".$_FILES['files']['name'];
$target = "images/" . $file;
//This gets all the other information from the form
$description=$_POST['Description'];
//Writes the Filename to the server
if(move_uploaded_file($_FILES['files']['tmp_name'], $target)) {
//Tells you if its all ok
echo "The file has been uploaded, and your information has been added to the directory";
//Writes the information to the database
mysql_query("INSERT INTO tbl_files (Filename,Description)
VALUES ('$file', '$description')") ;
} else {
//Gives and error if its not
echo "Sorry, there was a problem uploading the file.";
}

Answer 3

Your question is much too broad. Here are some tips. Come back with more specific questions after you have tried things.
"User" management is a non-trivial task. You need admin page(s) to create new users, delete users, etc. A "end-user" should not be a MySQL "user"; there should be only one or two MySQL users ("app-user"). The PHP code will validate an "end-user", using your own tables for storing their names, passwords, etc. The PHP code will connect to mysql as the app-user.
Media files should be stored on disk as files. This allows the easy use of HTML code to display images (<img...>) or play videos.
Thumbnails -- The simple answer is to treat them like other media. (In one project, I stored them in the db and clumsily converted them to base64 for inclusion in <img...>.)
Thumbnails -- There may be a thumbnail in the "exif data". But I would not trust it to exist. Instead, I would use image* routines in PHP to create a thumbnail from an image. (I do not know how to deal with thumbnails of videos.)
PHP has functions for uploading media. It is a bit clumsy and contorted; study the manual.
PHP is picky (for good security reasons) about access to the filesystem. You will need to poke holes (see open_basedir) to allow access.
You will need to pass information from one page to another. Keep in mind that HTML pages are "stateless", so nothing from one page is implicitly available to the next. You may be able to put everything in the url (...?user=123&img=abc...). But there could be security considerations. Or you may need to get "cookies" involved.
"The user clicks..." -- You may need JavaScript starting with OnClick=DoSomeFunction(...). You may need AJAX, but it does not sound like it.
Otherwise, HTML, PHP, and MySQL can handle everything you need.
Those notes probably encompass several thousand lines of PHP, including a several dozen SQL queries. Divvy up the project among your team so that not everyone has to be come versed in every aspect. Suggested breakdown: User management; Media processing; Flow of pages (clicks, passing args, security, etc); Database abstraction layer.