Как сравнить верный ли пароль и логин?

class DB
    {
        private static string connectionString = ConfigurationManager.ConnectionStrings["DB"].ConnectionString;
        private static SqlConnection connection = new SqlConnection(connectionString);
        public void openConnection()
        {
            if (connection.State == System.Data.ConnectionState.Closed)
                connection.Open();
        }
        public void closeConnection()
        {
            if (connection.State == System.Data.ConnectionState.Open)
                connection.Close();
        }
        public SqlConnection getConnection()
        {
            return connection;
        }
    }

<connectionStrings>
        <add name="DB" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\apoll\Desktop\ІПЗ\ІЗВП\IZVP13-16\DB.mdf;Integrated Security=True" />
    </connectionStrings>

private void buttonLogin_Click(object sender, EventArgs e)
        {
            String loginUser = LoginBox.Text;
            String passUser = PassBox.Text;
            DB db = new DB();
            DataTable table = new DataTable();
            SqlDataAdapter adapter = new SqlDataAdapter();
            //MessageBox.Show("SELECT*FROM [Table] WHERE Login='"+loginUser+"' AND Pass=" + passUser);
            db.openConnection();
            SqlCommand command = new SqlCommand("SELECT*FROM [Table] WHERE Login='"+loginUser+"' AND Pass="+ passUser, db.getConnection());
            SqlDataReader reader = command.ExecuteReader();
            MessageBox.Show($"{reader["Login"]}{reader["Pass"]}");
                if (reader.HasRows)
            { 
            MessageBox.Show("Успішно авторизовано");
            }
 
                else { MessageBox.Show("Спробуйте ще раз"); }
            reader.Close();
        }