Question

I got an Error at line myconn.Open(); How to solve it.

 {"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error:}


SqlConnection myconn = new SqlConnection();
        String connection = "Data Source=SQLEXPRESS;AttachDbFilename=C:\\Users\\Winer\\Documents\\Visual Studio 2008\\WebSites1\\App_Data\\Database.mdf";
        myconn.ConnectionString = connection;
        myconn.Open();

Can any one say about it ?

Answer 1

It just means that the server SQLEXPRESS was not found. I think you have a typo error. Try this if it works: (Data Source=.\SQLEXPRESS;)

String connection = "Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\Users\\Winer\\Documents\\Visual Studio 2008\\WebSites1\\App_Data\\Database.mdf";

UPDATE 1:

. means or equivalent to localhost

Data Source=.\SQLEXPRESS; is the same as Data Source=localhost\SQLEXPRESS;

or try

Data Source=YOURCOMPUTERNAME\SQLEXPRESS;

UPDATE 2

Why not use this Connection String format?

Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI;

OR

Data Source=myServerAddress;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;

WHERE

myServerAddress is your server address
myDataBase is the name of your database
myUsername is the username as well as
myPassword your password.

More ConnectionString format on this link.