dao2

public class UserDao
{
    private static string Host = "mydemoserver.postgres.database.azure.com";
    private static string User = "mylogin@mydemoserver";
    private static string DBname = "mypgsqldb";
    private static string Password = "<server_admin_password>";
    private static string Port = "5432";

    public User findById(int id)
    {
        var connectionString =
            String.Format("Server={0};Username={1};Database={2};Port={3};Password={4};SSLMode=Prefer",
                Host,
                User,
                DBname,
                Port,
                Password);

        using var dataSource = NpgsqlDataSource.Create(connectionString);
        using var command = dataSource.CreateCommand("SELECT some_field FROM some_table");
    }
}