title: PostgreSQL: How to assign null value to variable within function's parameter list?
body: <p>I am trying to assign null value to variable within function parameter list using PostgreSQL 9.3 version.  </p>
  
  <p><strong>Example</strong>: My try  </p>
  
  <pre><code> create or replace function fun_para(a varchar(20) =null, dt timestamp =null)
   ...
  </code></pre>
  
  <p>ERROR:  input parameters after one with a default value must also have defaults</p>