title: get rows without a specific date
body: <p>I have a DB2 table with below structure.</p>
  
  <p>Table has a column for accountno and another column for storing payment date.For the same account,every month multiple/single payments can happeni.e.,there will be multiple entries for the same accountno.</p>
  
  <p>I need to filter out the rows for which payment for a particular month is not present(payment date column).</p>
  
  <p>how can I frame the query for this?</p>
  
  <p>Thank you</p>