title: Oracle Sql: How do I avoid double occurrence in the result?
body: <p>I have two tables:<br/>
  table <strong>emp</strong> (a part of it):</p>
  
  <pre><code>ID|LAST_NAME
  ------------
  12|Giljum
  14|Nguyen
  </code></pre>
  
  <p>and <strong>ord</strong> (also only required information):<BR/></p>
  
  <pre><code>ID |SALES_REP_ID
  ---------------
  101|14
  106|12
  97 |12
  98 |14
  99 |14
  </code></pre>
  
  <p>I need to find the last names of employees that have handled the orders that have an id below 100.
  So i tried this:</p>
  
  <pre><code>SELECT E.last_name 
  FROM emp E,ord O
  WHERE E.id = O.sales_rep_id 
  AND O.id &lt; 100;
  </code></pre>
  
  <p>And the result is:</p>
  
  <pre><code>LAST_NAME
  ---------
  Giljum
  Nguyen
  Nguyen
  </code></pre>
  
  <p>And my question is, how to avoid the double occurrence of Nguyen, if possible without using a subquery.</p>