Problem with configuration file

[Sajo]

I want to create a connection to the server. The base is called NORTHWND. I wanted to create a connection using a configuration file. I created a configuration file. I want to get information about the version of the server I am using through the console application. However when I run the code I only get the following. It seems that I can´t log into database.

Here is the main code and code of config file
Main code

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Data.SqlClient;
using System.Configuration;

namespace ConsoleApp1
{
 
    class Program
    {
        static void Main(string[] args)
        {
          
            SqlConnection conn = new SqlConnection();
            conn.ConnectionString = ConfigurationManager.ConnectionStrings["Northwind"].ConnectionString;
            try
            {
                using (conn)
                {
                    // Try to open the connection.
                    conn.Open();
                    Console.WriteLine("Server Version: " + conn.ServerVersion);
                
                }
            }
            catch (Exception err)
            {
                // Handle an error by displaying the information.
                Console.WriteLine("Error reading the database. ");
                Console.WriteLine(err.Message);
            }
            conn.Close();
            Console.WriteLine("Now Connection Is:" + conn.State.ToString());

        }
    }
}

Here is the code of configuration file

<?xml version="1.0" encoding="utf-8" ?>


<configuration>
    <connectionStrings>
        <add name="Northwind" connectionString="Data Source=localhost;Initial Catalog=NORTHWND;Integrated Security=SSPI"/>
    </connectionStrings>

</configuration>

 

[Neal]

Did you misspell the database name?

 

[Sajo]

Did you misspell the database name?

No, the database name is NORTHWND.

 

[cbreemer]

No, the database name is NORTHWND.

Well, the SQL server sample database is called Northwind, so I would also suspect a typo here.
But if you are sure it should be NORTHWND, does this database actually exist ? The error message suggests that it doesn't. Have you tried accessing this db, with the same credentials, within SQL server ?

 

[Skydiver]

The screenshot on the OP seems to show that he is connected to the database under the "Data Connections" node on the left pane of Visual Studio. Unless he had to enter different credentials to make that connection, I would guess that he used his current identity just like in the connection string.

Also, the script for creating and populating the sample database uses the 8.3 name "northwnd.mdf":

https://raw.githubusercontent.com/microsoft/sql-server-samples/master/samples/databases/northwind-pubs/instnwnd.sql

All the OLEDB connection strings I found on Google use "NORTHWND", but all the SQL connection strings I've found use "Northwind". Since our OP is trying to use SQL, I would suggest trying "Northwind" just like @Neal and @cbreemer said.

 

[cbreemer]

The screenshot on the OP seems to show that he is connected to the database under the "Data Connections" node on the left pane of Visual Studio. Unless he had to enter different credentials to make that connection, I would guess that he used his current identity just like in the connection string.

Also, the script for creating and populating the sample database uses the 8.3 name "northwnd.mdf":

https://raw.githubusercontent.com/microsoft/sql-server-samples/master/samples/databases/northwind-pubs/instnwnd.sql

Yes indeed, I stand corrected. My SQL server expertise is getting a tad rusty since retirement

So it seems like VS can log on to this database, but the C# code can't. Spot the differences ?
The connection string says Data Source=localhost . Does the ODBC data source localhost exist, and if yes, how does is that configured ?
If the problem is not apparent, it could be an idea to enable ODBC logging and check the log for more detail.