Retrive Values from database table using asp.net

string commandText = "SELECT column1, column2 FROM MyTable Where Column1 IS NOT NULL"
var results = new DataSet();

var connectionString = ConfigurationManager
    .ConnectionStrings["MyConnectionStringName"].ConnectionString;

using (var connection = new SqlConnection(connectionString))
{
    connection.Open();
    using (var command = new SqlCommand(commandText, connection))
    {
        var adapter = new SqlDataAdapter(command);
        adapter.Fill(results);
    }
}

if (results.Tables.Count > 0)
{
    var firstTable = results.Tables[0];
    
    // Do something with the results
    foreach(var row in firstTable.Rows)
    {
        // do something??!
    }
}