title: Get all results from a table which doesn't have that combination in another table
body: <p>I have two tables on Oracle. Say:</p>
  
  <pre><code>table1:
  id    varchar2,
  name  varchar2,
  phone number,
  age   number,
  a     varchar2,
  b     varchar2,
  c     varchar2
  
  table2:
  z varchar2,
  a varchar2,
  b varchar2,
  c varchar2
  </code></pre>
  
  <p>I'm supposed to get all results from <code>table 1</code> that don't<br>
  have a combination of <code>a</code>, <code>b</code>, <code>c</code> on <code>table 2</code>.</p>
  
  <p>How can I do it?  </p>