title: distinct values from 2 tables
body: <p>assume I have 2 tables as below.</p>
  
  <pre><code>ID, NAME, NO
  1, PK,101
  2,AK,102
  3,OK,103
  
  ID,CITY,COUNTRY
  1,NY,US
  2,NJ,US
  </code></pre>
  
  <p>I need to get output as this, only the ID value</p>
  
  <pre><code>3
  </code></pre>
  
  <p>any help here.?</p>