Database connectivity error in Visual Studio?

Question

I have lost connectivity using Visual Studio 2012 database... when i try to reconnect and run the application then here us the Exception

NOTE: The previous file was deleted mistakenly, and trying to attach the new one it says it already exist? what is the Solution?

Answer 1

What kind of database are you running? Specify:

If you have SQLEXPRESS Database: First you need to change your Data Source name like this.

"Data Source=(LocalDB)\v11.0" to "Data Source=.\SQLEXPRESS"

To connect to your local SQL Server instance, issue the following string:

Server=.\SQLExpress;AttachDbFilename=C:\MyFolder\MyDataFile.mdf;Database=dbname Trusted_Connection=Yes;

To connect to your local SQL Server instance with a database file located in a data directory, issue the following string:

Server=.\SQLExpress;AttachDbFilename=|DataDirectory|mydbfile.mdf;Database=dbname Trusted_Connection=Yes;

To connect to LocalDB Automatic Instance, issue the following string:

Server=(localdb)\v11.0;Integrated Security=true;

To connect to LocalDB Automatic Instance with a specific data, issue the following string:

Server=(localdb)\v11.0;Integrated Security=true; AttachDbFileName=C:\MyFolder\MyData.mdf;

To connect to LocalDB named Instance, issue the following string:

Server=(localdb)\MyInstance;Integrated Security=true;

You need to get a string that matches your specific DB exactly, for it to connect.

Answer 2

In you connection string just add the 'database='. This prevents SQL server to create the auto-named database.