Cannot connect to SQL Server in Visual Studio

Question

I installed SQL Server and Visual Studio and tried to do my university project.

I can connect to SQL Server in Management Studio but can not connect in Visual Studio!

• Remote connecting is enabled
• all services are running
• and everything is ok but I dont know why I get this error :

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 the ...

What's wrong with this code?

 SqlConnection sqcon = new SqlConnection("Data Source=.;Initial Catalog=Badan_Sazi;Integrated Security=True");

 SqlCommand com = new SqlCommand();
 com.Connection = sqcon;
 com.CommandText = "SELECT tbl_morabi.family   as 'lname'  FROM tbl_morabi";

 com.Connection.Open();

I also tried ., localhost, my pc name ... same error anyway

• Visual Sudio 2012
• SQL Server Express 2012

Solution

SQL Server Express defaults to a SQLEXPRESS instance name

So try to use .\SQLEXPRESS or (local)\SQLEXPRESS as your server+instance name.

And if that doesn't work: what server name do you use in Management Studio to connect to your SQL Server instance?? Use that name!