title: Error while removing not null constraint for the not primary key column in sap hana
body: <p>My hana table have NOT NULL constraint on some columns.</p>
  
  <p>But when I am trying to remove that not null constraint from one of the column following error has occurred:</p>
  
  <blockquote>
    <p>Error: feature not supported: cannot add nullable constraints on primary key column</p>
  </blockquote>
  
  <p><strong>Note:</strong> <em>That column is not a  part of primary key.</em></p>
  
  <p>Syntax that I used for removing NOT NULL constraint:</p>
  
  <p>Syntax : </p>
  
  <pre><code>Alter table table_name alter (column_name datatype null)
  </code></pre>
  
  <p>Kindly suggest the solution.</p>