title: select from table a where record is not in table b and table c
body: <p>select from table a where record is not in table b and table c</p>
  
  <p>i have tried somtihing like this</p>
  
  <pre><code>    select a.* from table a
  left outer join b on b.index=a.index
  left outer join c on c.index=a.index
  </code></pre>
  
  <p>Thanks</p>