title: Nullable return type in oracle function
body: <p>Is it possible to return null from an oracle function?</p>
  
  <p>I have the following oracle function:</p>
  
  <pre><code>create or replace function vta.GetAmount(p_month NUMBER)
    return number is
    v_amount number(9);
  begin
    select amount
      into v_amount
      from salary
     where salary.month = p_month;
    return v_amount;
  end GetAmount;
  </code></pre>
  
  <p>When the select statement returns zero rows, it raises the following exception:
  <code>ora-01403: no data found</code>.</p>
  
  <p>In this case I would like that the function returns null.</p>