Question

I am trying to create a document manager for my winforms application. It is not web-based.

I would like to be able to allow users to “attach” documents to various entities (personnel, companies, work orders, tasks, batch parts etc) in my application.

After lots of research I have made the decision to use the file system to store the files instead of a blob in SQL. I will set up a folder to store all the files, but I will store the document information (filepath, uploaded by, changed by, revision etc) in parent-child relationship with the entity in an sql database.

I only want users to be able to work with the documents through the application to prevent the files and database records getting out of sync. I some how need to protect the document folder from normal users but at the same time allow the application to work with it. My original thoughts were to set the application up with the only username and password with access to the folder and use impersonation to login to the folder and work with the files. From feedback in a recent thread I started I now believe this was not a good idea, and working with impersonation has been a headache.

I also thought about using a webservice but some of our clients just run the application on there laptops with no windows server. Most are using windows server or citrix/windows server.

What would be the best way to set this up so that only the application handles the documents?

Answer 1

I’d go with these options, in no particular order.

1. Create a folder on the server that’s not accessible to users. Have a web service running on the server (either using IIS, or standalone WCF app) that has a method to upload & download files. Your web service should manage the directory where the files are being stored. The SQL database should have all the necessary metadata to find the documents. In this manner, only your app can get access to these files. Thus the users could only see the docs via the app.

2. I can see that you chose to store the documents on the file system. I wrote a similar system (e.g. attachments to customers/orders/sales people/etc…) except that I am storing it in SQL Server. It actually works pretty well. I initially worried that so much data is going to slowdown the database, but that turned out to be not the case. It’s working great. The only advice I can give if you take this route is to create a separate database for all your attachments. Why? Because if you want to get a copy of the RDBMS for your local testing, you do not want to be copying a 300GB database that’s made up of 1GB of actual data and 299GB of attachments.

3. You mentioned that some of your users will be carrying laptops. In that case, they might not be connected to the LAN. If that is the case, I’d consider storing the files (and maybe metadata itself) in the cloud (EC2, Azure, Rackspace, etc…).