title: Error in Oracle BI expression
body: <p>I am trying to check if the field is 0 or null and if so, the remaining amount will be equal the invoice amount. </p>
  
  <p>This error appears and I searched for it but I found nothing!</p>
  
  <p><a href="https://i.stack.imgur.com/Rde3x.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Rde3x.png" alt="enter image description here"></a></p>
  
  <p>Here is the code:</p>
  
  <pre><code>IF (G_Invoice.Amount_Paid = 0 OR G_Invoice.Amount_Paid is null )
  
  then
  
  Remaining_Amount := G_Invoice.Invoice_Amount
  
  else
  
  G_Invoice.Invoice_Amount-G_Invoice.Amount_Paid
  
  end if;
  </code></pre>