Keep in mind that App_Data allows you to use a file based SQL Server database :)
You can try this:
Choose "Add New Data Source" from the Data menu.[And follow the connection wizard]
If you don't have a Data menu, do the following:
*Click on Tools >>Connect to Database...
*Select "Microsoft SQL Server Database File", take the default Data provider, and click OK
*On the next screen, browse to your Database file, which will be in your VS Solution folder structure somewhere.
Test the connection. If you want to add the string to the web.config, click the Advanced button, and copy the Data Source line (at the bottom of the dialog box), and paste it into a connection string in the appropriate place in the web.config file. You will have to add the "AttachDbFilename" attribute and value. Example:
The raw text from the Advanced panel:
Data Source=.\SQLEXPRESS;Integrated Security=True;Connect Timeout=30;User Instance=True The actual entry in the web.config:
<add name="SomeDataBase" connectionstring="Data Source=.\SQLEXPRESS; AttachDbFilename=C:\Development\blahBlah\App_Data\SomeDataFile.mdf; Integrated Security=True; Connect Timeout=30; User Instance=True" />
- or -
In your Solution Add New Project (Database Project)
While adding this project, it asks for database connection, provide your databse connection, or you can specify default database later using Set Default Reference.
You can find this facility by right clicking on database project. now your asp.net allow u to run query from visual studio..
And another good place to check is the following link.
http://connectionstrings.com/
Good luck