To test a web app I am working on, I created a database using Visual Studio and placed it in the folder App_Data, where an .mdf file was created as part of adding the database.

I tried to setup a connection string in Web.Config to allow my ASP.NET and C# code to access the database, but none of the connection strings I tried worked. I was able to get connection strings to work correctly when connecting to a SQL Server database across the network, but was not able to get a working connection string to work with the database added to the ASP.NET project.

I even tried some strings found on sites like, but was unable to get those to work either.

Any help will be appreciated.

Michael G. Workman