title: need to show only the duplicate value in sql
body: <p>i have table as</p>
  
  <pre><code>id----name----roll-----class
   1----ram-------1-----2
   2----shyam-----2-----3   
   3----ram-------1-----3
   4----shyam-----2-----3
   5----ram-------1-----2
   6----hari------1-----5
  </code></pre>
  
  <p>i need to find the the duplicate row only that have common <strong>name, roll, class</strong>. so the expected result for me is.</p>
  
  <pre><code>    id----name----roll-----class
       1----ram-------1-------2
       2----shyam-----2-------3           
       4----shyam-----2-------3
       5----ram-------1-------2
  </code></pre>
  
  <p>i tried to get from the query below but here only one field is supported. i need all three field common. Please do help me in this. thanks</p>
  
  <pre><code>SELECT * 
  FROM table 
  WHERE tablefield IN ( 
   SELECT tablefield
   FROM table 
   GROUP BY tablefield  
   HAVING (COUNT(tablefield ) &gt; 1) 
  ) 
  </code></pre>