title: date interval in sql coding
body: <p>I have a table like below:</p>
  <pre><code>Creationdate         Priority             interval
  10/10/2020             P0                    1
  7/10/2020              P1                    7
  </code></pre>
  <p>I want to add the interval to each date. for example if the priority is p0 then creationdate+1,</p>
  <p>The problem is the date is stored as string.  How can I get the result?</p>