title: retrieving duplicate records through sql
body: <p>I have a data like</p>
  
  <pre><code>paper Id Author Id  
  
  1          15
  2          13 
  3          12
  3          11 
  4          10
  4          10
  4          9 
  </code></pre>
  
  <p>I want to select papers having multiple authors.So my data should look like </p>
  
  <pre><code>paper Id   Author Id
  3            12
  3            11
  4            10
  4             9
  </code></pre>
  
  <p>I tried with sql query :</p>
  
  <pre><code>statement&lt;-"SELECT PaperId,AuthorId,COUNT(PaperId) 
              FROM author_data_pap_aut
              GROUP BY PaperId,AuthorId
              HAVING ( COUNT(*) &gt;1 )"
  </code></pre>
  
  <p>But its not working.How can i get the desired result</p>
  
  <p>Thanks </p>