title: add record if id is not known else update the record
body: <p>I have the following table in mariadb:</p>
  
  <p>-id = key which shall autoincrement
  -price
  -amount
  -name
  -order_id</p>
  
  <p>order_id can appear twice in the table but the combination of name and order_id should be unique. I now have a combination of name and order_id. </p>
  
  <p>What I want to do is to add a record if the combination of name and order_id is not in the table.
  If it's in then I want to change/get the amount value.</p>
  
  <p>Is there a nice query to accomplish this?</p>
  
  <p>Regards</p>