среда, 7 января 2015 г.

Cannot attach the file as database / The underlying provider failed on Open

Check your connection strings. If you're on a new computer you may need to change them somewhat or open a port in the firewall.

One simple way to get the proper connection string is to connect to the DB Server and view the properties.


  1. Open SQL Server Object Explorer (View > SQL Server Object Explorer)
  2. Connect to the DB Server (Click "Connect to Server" and enter "(LocalDB)\v11.0")
  3. Right click on the appropriate DB and select "Properties"
  4. View the connection string
And Try it this way:
Open the "Developer Command Propmpt for VisualStudio" under your start/programs menu. Run the following commands:

sqllocaldb.exe stop v11.0
sqllocaldb.exe delete v11.0