title: Issue in generating Query
body: <p>I am having two tables <code>cdr</code> and <code>cdr_01</code></p>
  
  <pre><code>////Cdr////
  id calling_no called_no call_date duration
  1 9899767876 0112356788 01-jan-2012 160
  2 9999758743 0244356788 01-jan-2012 191
  
  ////cdr_01/////
  id calling_no called_no call_date duration
  1 9999758743 0244356788 01-jan-2012 190
  2 9899767876 0112356788 01-jan-2012 163
  </code></pre>
  
  <p>I want output corresponding to the two tables by matching each column instead of id
  and if difference of duration is -1, 0 , 1 than that is to be ignore rest to be displayed.</p>
  
  <p>output :</p>
  
  <pre><code>calling_no called_no call_date duration
  9899767876 0112356788 01-jan-2012 163
  </code></pre>
  
  <p>Please help.</p>