title: Case statement problem to show values without null in a row
body: <pre><code>select  CASE WHEN ( rtt.us_code = 's' )
                    THEN rtt.name
                    ELSE '' END AS input_tax_name,
               CASE WHEN ( rtt2.us_code = 'r')
                    THEN rtt2.name
                    ELSE '' END AS output_tax_name,
               CASE WHEN ( rtt.us_code = 's' )
                    THEN rtt.acc_id
                    ELSE 0 END AS input_tax_rate,
               CASE WHEN ( rtt2.us_code = 'r')
                    THEN rtt2.acc_id
                    ELSE 0 END AS output_tax_rate
  from supplier_item si
  JOIN ret_tx_type  rtt
  ON si.ret_tx_type_id = rtt.ret_tx_type_id
  JOIN ret_tx_type  rtt2
  ON si.ret_tx_type_id = rtt2.ret_tx_type_id
   where si.ret_tx_type_id is not null
  </code></pre>
  
  <p>I am trying to display input and output tax in the same row for a report depends on us_code is 'r' and 's'.
  But i am getting the results like</p>
  
  <p>if input tax is there ...output tax column will be null
  if output tax is there ...input tax column will be null</p>
  
  <p>i am want to get the both in same row and no need to make null in any rows</p>
  
  <p>please help</p>