When creating a new database with SQL Server Express 2005, the database files (.mdf and .ldf) get stored in C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data by default.
However, with the tutorials I’ve seen for ASP.NET MVC (e.g., Nerd Dinner), it seems to be common practice to keep the database files in the ASP.NET project’s App_Data folder.
Questions
- Is there any significance to the App_Data folder, or is it just a convenient place to store database files if you happen to use Visual Studio’s designer to create a new database?
- Will there be any negative repercussions if I don’t use or even delete the App_Data folder?
Update
One thing I’m still not getting. If you have a production database on the server, why would you even want to replace this database with what is in App_Data. Wouldn’t you normally just want to have update scripts that you run on the production database when you release a new version of the app? Even for initial deployment, I’d rather script database creation than physically copy over the files. Also, with SQL Server (Express) databases, copying is not enough. You have to detach the database to manipulate the files then reattach when you are done.
So, I have to say, the point of App_Data still escapes me. Can someone enlighten me?
You can delete App_Data without any negative repercussions, but when it exists (by folder name) inside an ASP.NET website then it has the special website power of disallowing direct linking to download its contents – this is a security feature to protect your database from being downloaded directly over the web (e.g. by a web browser) even though it exists in the website. However your application can still access the files in the App_Data folder just as it accesses other website content.
Microsoft states it as:
Microsoft describes their special ASP.NET folder structures including App_Data here.