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I am implementing an image upload system in PHP, The following are required:
Have categories
Allow users to comment on images
Allow rating of images
For that, I have 2 approaches in mind:
1. Implement the categorization by folders
Each category will have its own folder, and PHP will detect categories via those folders.
Pros
Structured look, easily locatable images.
Use of native PHP functions to manipulate and collect information about folders and files
Cons
Multiple categorization is a pain
Need to save the full path in the database
2. Implement the categorization by database
Each image in the database will have a catID (or multiple catIDs), and PHP will query the database to get the images
Pros
Easily implemented multi-categories
Only image name is saved
Cons
Seems more messy
Need to query the database a lot.
Which do you think is better? Or is there a third, completely different, approach that I'm missing?
Just a note, I don't need code, I can implement that myself, I'm looking to find what to implement.
Would love to hear from you.
I believe that the second option is better, a DB is giving you much more flexibility, and I think better performance then file system, if you set the right indexes.
In the filesystem approach you are limited to only 1 category per image, when in the DB you can set multiple categories on an image.
The con that Db is more messy, sorry I can't find a reason way in the db it will be more messy, maybe you mean that the files are not organized on the file system, but you still need to organize the files on the file system and divide them to multiple folders for better performance, and if you want to get all the images that have been uploaded you query the db for all of them, which will be much faster then ls on all the categories folders.
In organize the files in the file system when using the DB approach I mean that you need to divide them to several folders, actually it depends on how you predict the upload of the images will be:
If you predict that the upload will be spread on long time then I think that better to put the files in directories per range on time(day, week, month) example if I upload an image now it will go to
"/web_path/uploaded_photos/week4_2012/[some_generated_string].jpg"
If you don't know how to predict the uploads, then I suggest you will divide the files into folders on something generic like the first two letters in MD5 hash on the image name, for example if my file name is "photo_2012.jpg" the hash will be "c02d73bb3219be105159ac8e38ebdac2" so the path in the files system will be "/web_path/uploaded_photos/c/0/[some_generated_string].jpg"
The second con that need to query the DB a lot is not quite true, cause you will need the same amount of queries on the file system which are far more slower.
Good luck.
PS
Don't you forget to generate a new file name to any image that have been uploaded so there will be no collisions in different users uploaded same image name, or the same user.
I'd be inclined to go with the database approach. You list the need to query the database a lot as a con, but that's what databases are built for. As you pointed out yourself, a hierarchical structure has serious limitations when it comes to items that fall into more than one category, and while you can use native PHP functions to navigate the tree, would that really be quicker or more efficient than running SQL queries?
Naturally the actual file data needs to go somewhere, and BLOBS are problematic to put it mildly, so I'd store the actual files in the filesystem, but all the data about the images (the metadata) would be better off in a database. The added flexibility the database gives you is worth the work involved.
The second solution (database) is actually a TAG/LABEL system of categorizing data.
And that is the way to go, biggest examples being Gmail and Stackoverflow.
Only thing you need to be careful about is how to model tags. If the tags are not normalized properly, querying from database becomes expensive.
Use folders only to make file storage reliable, storing certain amount of files per folder, i.e.
/b/e/beach001.jpg
as for your dilemma, it is not a question at all.
From your conditions you can say it yourself that database is the only solution.
Since you need a database to store comments and ratings, you should store categories in database as well. Sometime later you may also want to store image captions and description; database allows you to do that. And I would not worry about querying the database a lot.
Whether to store the image itself in database or filesystem is a separate issue which is discussed here.
Note about storing images in filesystem: do not store thousands of images in a single directory; it could cause performance issues for the OS. Instead invent a way to organize images in sub directories. You can group them by dates, filenames, randomly etc. Some conventions:
upload date: month/year
/uploaded_images
/2010/01
/2010/02
upload date: month-year
/uploaded_images
/2010-01
/2010-02
md5 hash of image name: first character
/uploaded_images
/0/
/1/
.
.
.
/e/
/f/
batches of thousands
/uploaded_images
/00001000/
/00002000/
/00003000/
I eventually went with the best answer of this question: Effeciently storing user uploaded images on the file system.
It works like a charm. Thanks for all of the answers!
I want to create flex/actionscript directory view for my files with php/mysql. I have some ideas that I want to share:
1)I am thinking of creating table (in mysql) "files" and another table "folders", when user loges in i will require all data from "files" and "folders" where Username = 'something'. But the problem is, I will create a lot of entries inside of tables. For example if I will have 100 users, and each user could create 100 entries (files or folders) it means that i will get 10000 entries inside table.
2)My second idea, and I think more safe way of doing it is creating table "users" where will be set id, username, password, ... , files, folders. In files (text format entry) will be listed information about files, and they will be dividend by "*" symbol like this:
id*file name*size(in kbytes)*path*status
example:
15*test.exe*150*/root/*private
16*test2.exe*200*/root/folder1/*public
17*test3.exe*5600*/root/folder1/subfolder/*private
...
This info will be outputed when flex once when user loges in, and actionscript will catch it. But the problem is that when i will edit 1 file info (for example 1 file name "test.exe" to "editedtest.exe") i will load back in mysql all data:
15*editedtest.exe*150*/root/*private
16*test2.exe*200*/root/folder1/*public
17*test3.exe*5600*/root/folder1/subfolder/*private
Now here is only 3 file info but there can be more than 1000.
so what do you think, how can I solve my task? Or is it better way of doing it and I just don't know about it? Please write your suggestions and thoughts.
I will use the term "filesystem" to represent the file/folders structure for each user.
Do not be afraid of a huge amount of lines in your db, databases are designed to handle this.
Also, i
t provides you many advantages :
lazy loading : in you directory tree, you can fetch only the root directories/files for the current user, and when the user wants to go in a subfolder, you can load the content of this subfolder. If you store the whole filesystem structure in a string, you have to load the entire structure even if you do need just one line
unit updates : with a database, you can update a file/folder without loading the full filesystem structure
less code : you won't have to parse the text string to re-create the path, you can store it "as is" in the database
indexation : if you store one file/folder per row, you can index these to accelerate searches. If you store the entire filesystem structure in it's owner row, you cannot perform searches efficiently.
How to accomplish:
Save in mysql what user has access to what sub directory.
Write a PHP script that reads the directory that has been queried by the Flash application. Check if the directory belongs to the user. Return all files of that directory. Show navigation buttons in Flash the same way as the web server shows the buttons in directoy listing pages such as: http://www.css-zibaldone.com/articles/directory/examples/3/3.html (googled for apache directory listing example).
This approach will perform 1 directory traversal per request. You can then refine this situation by enabling the traversal to return the current directory and also its direct child directory files. Or you cache the results in some files on the hard disk.
I found a file browser app for AJAX: http://www.ajaxfilebrowser.com/
Given a PHP bug tracker project with an SQL DB (MySQL, PostgreSQL, Oracle...), which should be able to store attached files for each bug.
How would you basically store info (file info and the file itself) on DB & disk?
e.g.
DB: the table bug would have a related table bug_files having a bug_id field, and a filename field containing path to file on disk
Disk: storing files in an efficient way (avoiding having too many files in a single directory), e.g. automatically create directories 1-1000, 1001-2000, etc. so we can have /1001-2000/1234/bugfile.jpg or random subdirectories like /z/e/x/q/1000_bugfile.jpg ?
...or are there a more efficient ways?
Thanks.
EDIT
It also depends on how you want to get
to these files, do you use a back-end
webpage that fetches all bugs and
creates the links for you? Or do you
get an e-mail after a bug occured and
do you have to find it manually? I
don't think this choice mathers a lot.
Files would be listed / uploaded / downloaded through the bug tracking web application (=> HTTP upload / download).
Nobody except developers / sysadmins would be able to view the automatically generated directory structure (however it would be more convenient to have a "clear" structure).
I'd let the file system do its job (file storage). Databases can be used for file storage but it's not (generally) as efficient, e.g. the file data may be put in the database buffers - this in itself isn't bad, but it may take resources away from other tables, row data and reduce the performance of other queries.
Creating directories based on a meaningful combination of date and project names etc. would help reduce the performance loss when having many files in the same directory.
I'd strongly suggest using recognizeable directory structure, perhaps even date based or something that matches up with (parts) of your bug filename. F.e. '20110506-bugfile' would be in /2011/05/06/ Perhaps this is a little to matching and only 2011/05/ would be enough.
It also depends on how you want to get to these files, do you use a back-end webpage that fetches all bugs and creates the links for you? Or do you get an e-mail after a bug occured and do you have to find it manually? I don't think this choice mathers a lot..
A slightly different option is to add the file into your database in the table bug (http://www.php-mysql-tutorial.com/wikis/mysql-tutorials/uploading-files-to-mysql-database.aspx), then you don't have to create a directory structure, BUT, this would not allow you to find the files using an FTP ofcourse.
I was wondering what is the best way to store a users upload images like an avatar and so on using PHP and MySQL? Where should I begin? And is there a good article on this?
"Best" depends on what your goal is.
The two primary ways of storing user-uploaded images are either putting the binary content into the database as a BLOB, or storing the images to the drive somewhere and putting an entry into the database indicating which image belongs where.
Placing the images in the database has the advantage of not requiring any sort of filesystem permissions on the webserver, and removes any sort of syncing issues if you're serving up the site off of multiple webservers. However, over time it makes your database huge, and if you don't design your tables correctly, it can absolutely kill your performance and scalability.
Storing the images as file on the file system has the added advantage of making retrieval extremely quick and efficient, since webservers are very good at serving static files.
Edited to add
If you decide to store file content in the database, absolutely do not put it in a table that needs to be accessed quickly. If, for example, you have a "users" table that is searched on nearly every pageview, then that table is not the place to put your file contents. Instead, create a separate "images" or "files" table containing the file and related meta-information.
Putting a lot of bytes per row into a table makes that table very slow to work with. You don't want that kind of thing in tables that see heavy use.
Images should really be stored on the file system for a couple of reasons:
Proxying and If-Modified-Since web requests: Apache can process If-Modified-Since HTTP headers for you and return a 304 response, and that's about the best performance you can get. Reverse Squid proxies and proxies posted at ISPs will attempt to take advantage of this.
Virus scanning: if you allow any file uploads, jerks will try and upload scary stuff to see if they can bust your site. It's not unreasonable to want to run ClamAV or the like against your user uploads to see if there's trouble afoot. You wouldn't want to tie up your database if you wanted to scan the records for malware.
Schema simplicity: If you allow file uploads, you'll also need to add meta data about the MIME-type, file size, height and width. If the file itself doesn't match the MIME-type in the table, then you need to code a select from the table and stream it into /usr/bin/file. It can be much simpler to shell_exec( "/usr/bin/file /path/to/mumble" ).
Thumb-nailing: user image uploads are likely to need to be thumb-nailed, and this is often much easier done asynchronous to the actual web request. It's really not fun when some well meaning user attempts to upload a 150MB photoshop file given to them by their professional photographer buddy, and your apache instance goes OOM when attempting to load the ImageMagick library in the memory space of the web worker. This really doesn't scale for apache workers. Create a work queue/cron job outside of Apache to handle this work.
Table corruption: Wow, you don't really want to cripple all user avatars if your MySQL index file gets borked and you need to do an offline table repair on that table.
Backup and restore: You don't really want to lock a large table with mysqldump. Using rsync will save you a lot of time and give you much more flexibility. Tables are typically restored a whole table a time--tables are not typically backed up in smaller pieces.
make a new directory on your server for each user with the user id being the name of the directory and save the user's images inside it. whenever you want to display the user's image:
<img src="<path>/users_images/<user_id>/thumb.gif" />
If I were you, I would just save the image somewhere in your sites directory and then save the link to the image in MySQL, if you really want to save it in a database, I would read it into a string and then base64_encode() it and then save it in the database.
There are all sorts of little troubles you will face by storing them in a database, you will have to create scripts to echo them back out ect, and the server and database load will be greatly increased. If I were you, I'd just store the reference.
I suggest having a table where you store user data like username, first name. In that table create a field called something like "avatar" in which you can store a file reference.
Assuming your user avatars are stored in: htdocs/images/avatars/
And user apikot has the avatar "avatar.jpg" stored agains it's user in the database, you could then compile the following url when generating an image tag: "/htdocs/images/avatars/avatar.jpg".
Here's an example of storing the image in binary on a MySQL database. I'm not too sure if there are any advantages or not to that. I'll leave it for someone else to comment.
Another way you could do it is store the location of the image in a column and query it for referencing.
Create a BLOB type field, and insert the result of file_get_contents( $ImageFile )
I have built a small web application in PHP where users must first log in. Once they have logged in, I intend on showing a small thumbnail as part of their "profile".
I will have to ensure the image is below a particular size to conserve space, or ensure it is a particular resolution, or both, or even perhaps use something like image magick to scale it down.
Not sure what the best approach for that is yet, any ideas welcome.
Also, I have been trying to work out if it is better to store the image in the users table of MySQL as a blob, or maybe a separate images table with a unique id, and just store the appropriate image id in the users table, or simply save the uploaded file on the server (via an upload page as well) and save the file as theUsersUniqueUsername.jpg.
Best option?
I found a tutorial on saving images to mysql here:
http://www.phpriot.com/articles/images-in-mysql
I am only a hobby programmer, and haven't ever done anything like this before, so examples, and/or a lot of detail is greatly appreciated.
Always depends of context, but usually, I store a user image on the filesystem in a folder called /content/user/{user_id}.jpg and try to bother the database as little as possible.
I would recommend storing the image as a file and then have the file URI in the database. If you store all the images in the database, you might have some problems with scaling at a later date.
Check out this answer too:
Microsoft's advice for SQL Server used to be, for speed and size, store images in the file system, with links in the database. I think they've softened their preference a bit, but I still consider it a better idea certainly for size, since it will take up no space in the database.
The overhead using BLOB is a lot less than most people would have you believe, especially if you set it up right. If you use a separate server just running the DB to store binary files then you can in fact use no file-system at all and avoid any overhead from the file-system
That said the easiest/best way unless you have a couple of servers to yourself is storing them in the filesystem
Do not store the absolute URL of the file in your DB, just the unique part (and possibly a folder or two), e.g. 2009/uniqueImageName.jpg or just uniqueImageName.jpg.
Then in your pages just add the host and other folders onto the front, that way you have some flexibility in moving your images - all you'll need to change is a line or two in your PHP/ASP.NET page.
There is no need to store outside the document root for security - a .htaccess file with DENY FROM ALL will work the same and provide more flexibility
No need to 'shunt' images so much for security, just have a getImage.php page or something, and then instead of inserting the actual URL in the src of the image, use something like getImage.php?file=uniqueImageName.jpg.
Then the getImage.php file can check if the user is authorised and grab the image (or not).
Use a name which is guaranteed to be unique (preferably an integer i.e. primary key) when storing, some file-system (i.e. Windows) are case-insensitive, so JoeBloggs.jpg and joebloggs.jpg are unique for the database, but not for the file-system so one will overwrite another.
Use a separate table for the images, and store the primary key of the image in the users table. If you ever want to add more fields or make changes in future it will be easier - it's also good practice.
If you are worried about SEO and things like that, store the image's original file name in another field when you are uploading, you can then use this in your output (such as in the alt tag).
Challenging the Conventional Wisdom!
Of course it is context dependent, but I have a very large application with thousands of images and documents stored as BLOBS in a MySQL database (average size=2MB) and the application runs fine on a server with 256MB of memory. The secret is correct database structure. Always keep two separate tables, one of which stores the basic information about the file, and the other table should just contain the blob plus a primary key for accessing it. All basic queries will be run against the details table, and the other table is only access when the file is actually needed, and it is accessed using an indexed key so performance is extremely good.
The advantages of storing files in the database are multiple:
Much easier backup systems are required, as you do not need to back up the file system
Controlling file security is much easier as you can validate before releasing the binary (yes, you can store the file in a non-public directory and have a script read and regurgitate the file, but performance will not be noticeably faster.
(Similar to #1) It cleanly separates "user content" and "system content", making migrations and cloning easier.
Easier to manage files, track/store version changes, etc, as you need fewer script modifications to add version controls in.
If performance is a big issue and security and backups aren't (or if you have a good fs backup system) then you can store it the the FS, but even then I often store files (in the case of images) in the DB and building a caching script that writes the image to a cache folder after the first time it's used (yes, this uses more HD space, but that is almost never a limiting factor).
Anyway, obviously FS works well in many instances, but I personally find DB management much easier and more flexible, and if written well the performance penalties are extremely small.
We created a shop that stored images in the DB. It worked great during development but once we tested it on the production servers the page load time was far too high, and it added unneccessary load to the DB servers.
While it seems attractive to store binary files in the DB, fetching and manipulating them adds extra complexity that can be avoided by just keeping files on the file system and storing paths / metadata in the DB.
This is one of those eternal debates, with excellent arguments on both sides, but for my money I would keep images away from the DB.
I recently saw this tip's list: http://www.ajaxline.com/32-tips-to-speed-up-your-mysql-queries
Tip 17:
For your web application, images and other binary assets should normally be stored as files. That is, store only a reference to the file rather than the file itself in the database.
So just save the file path to the image :)
I have implemented both solutions (file system and database-persisted images) in previous projects. In my opinion, you should store images in your database. Here's why:
File system storage is more complicated when your app servers are clustered. You have to have shared storage. Even if your current environment is not clustered, this makes it more difficult to scale up when you need to.
You should be using a CDN for your static content anyways, and set your app up as the origin. This means that your app will only be hit once for a given image, then it will be cached on the CDN. CloudFront is dirt cheap and simple to set up...there's no reason not to use it. Save your bandwidth for your dynamic content.
It's much quicker (and thus cheaper) to develop database persisted images
You get referential integrity with database persisted images. If you're storing images on the file system, you will inevitably have orphan files with no matching database records, or you'll have database records with broken file links. This WILL happen...it's just a matter of time. You'll have to write something to clean these up.
Anyways, my two cents.
What's the blob datatype for anyway, if not for storing files?
If your application involves authorisation prior to accessing the files, the changes are that you're a) storing the files outside of DOCUMENT_ROOT (so they can't be accessed directly; and possibly b) sending the entire contents of the files through the application (of course, maybe you're doing some sort of temporarilly-move-to-hashed-but-publicly-accessible-filename thing). So the memory overhead is there anyway, and you might as well be retrieving the data from the database.
If you must store files in a filesystem, do as Andreas suggested above, and name them using something you already know (i.e. the primary key of the relevant table).
I think that most database engines are so advanced already that storing BLOB's of data does not produce any disadvantages (bloated db etc). One advantage is that you don't have any broken links when the image is in the database already. That being said, I have myself always done so that I store the file on disk and give the URI to the database. It depends on the usage. It may be easier to handle img-in-db if the page is very dynamic and changes often - no namespace -problems. I have to say that it ends down to what you prefer.
I would suggest you do not store the image in your db. Instead since every user will be having a unique id associated with his/her profile in the db, use that id to store the image physically on the server.
e.g. if a user has id 23, you can store an image in www.yourname.com/users/profile_images/23.jpg. Then to display, you can check if the image exists, and display it accordingly else display your generic icon.
As the others suggested:
Store the images in the filesystem
Do not bother to store the filename, just use the user id (or anything else that "you already know")
Put static data on a different server (even if you just use "static.yourdomain.com" as an alias to your normal server)
Why ?
The bigger your database gets the slower it will get.
Storing your image in the database will increase your database size.
Storing the filename will increase your database size.
Putting static data on a different server (alias):
Makes scaling up a lot easier
Most browsers will not send more than two requests to the same server, by putting static data on a "second" server you speed up the loading
After researching for days, I made a system storing images and binaries on the database.
It was just great. I have now 100% control over the files, like access control, image sizing (I don't scale the images dynamically, of course), statistics, backup and maintenance.
In my speed tests, the sistem is now 10x slower. However, it's still not in production and I will implement system cache and other optimizations.
Check this real example, still in development, on a SHARED host, using a MVC:
http://www.gt8.com.br/salaodocalcado/calcados/meia-pata/
In this example, if a user is logged, he can see different images. All products images and others binaries are in DB, not cached, not in FS.
I have made some tests in a dedicated server and results were so far beyond the expectations.
So, in my personal opinion, although it needs a major effort to achieve it, storing images in DB is worth and the benefits are worth much more the cons.
As everybody else told you, never store images in a database.
A filesystem is used to store files -> images are files -> store them in filesystem :-)
Just tested my img's as blob, so. This solution working slower than images on server as file. Loading time should be same with images from DB or http but is't. Why? Im sure, when images are files on server, browser can caching it and loading only once, first time. When image going form DB, every time is loaded again. That's my oppinion. Maybe Im wrong about browser caching, but working slower (blob). Sry my English, whatever ;P
These are the pros of both solutions
In BLOBS :
1) pros : the easiness to mange clusters since you do not have to handle tricky points like file syncs between servers
2) DB backups will be exhaustive also
In files
1) Native caching handly (and that's the missing point of previous comments, with refresh and headers that you won't have to redesign in DB (DB are not handling last modification time by default)
2) Easiness of resizing later on
3) Easiness of moderation (just go through your folders to check if everything is correct)
For all these reasons and since the two pros of databases are easier to replicate on file system I strongly recommend files !
In my case, i store files in file system. In my images folder i create new folder for each item named based on item id (row from db). And name images in an order starting from 0. So if i have a table named Items like this:
Items
|-----|------|-----|
| ID | Name | Date|
|-----|------|-----|
| 29 | Test1| 2014|
|-----|------|-----|
| 30 | Test2| 2015|
|-----|------|-----|
| 31 | Test3| 2016|
|-----|------|-----|
my images directory looks like something like:
images/
29/
30/
31/
images/29/0.png
images/29/1.jpeg
images/29/2.gif
etc.