This tutorial will show you how you can connect to MS SQL server using ASP.Net C#.

First of all, you will need to import the SqlClient namespace into your project or site page.

    
//required sql namespace
using System.Data.SqlClient;

The following quick function will connect to the MS SQL server. Basically it defines the SqlConnection object and attaches a connection string value into the object. The .Open() method will try to connect to the server and .Close() method basically will close the database connection.

    
//private function for testing connection
private void ConnectToSQL() {
    string connectionString = @"Data Source=\SQLEXPRESS;Initial Catalog=DBNAME_HERE;User ID=USERNAME_HERE;Password=PASSWORD_HERE";
    using (SqlConnection objSqlConnection = new SqlConnection(connectionString)) {
        try {
            objSqlConnection.Open();
            objSqlConnection.Close();
            Response.Write("Connection is successfull");
        } catch (Exception ex) {
            Response.Write("Error : " + ex.Message.ToString());
        }
    }
}

To test it, you can call the function in the Page_Load method just to see what will happen. Remember to set the connectionstring correctly according to your setting.