title: How to create a trigger based on a column value change from "S" to "D"
body: <p>I have a scenario where I need a trigger to report whenever the column <code>src_system_id</code> on the table <code>purch_ord_hdr</code> gets changed from “S” to “D”.</p>
  
  <p>The action must be triggered by <code>insert</code> or/and <code>update</code> based whenever the value changes. No matter if it is a <code>insert</code> or <code>update</code> statement.</p>