title: SQL - for loop duplicate issue
body: <p>Just wondering how I would change the following SQL so that the insert only happens for unique link_row instances.  So if the exact same values are pulled back in the seletc I only want to do the loop and insert the first time.</p>
  
  <pre><code>BEGIN   
        FOR LINK_ROW IN ( SELECT LINKTEXT, LINKURL, CORPID FROM LINKS )
        LOOP
            //Do insert here
  </code></pre>
  
  <p>When I run the script I get errors on the primary key violation as the same item is being inserted twice inside the loop.</p>
  
  <p>Thanks in advance</p>