title: what is the default value for "Timestamp with zone" in pgsql?
body: <p>I am using following code to have default value if column has null value.
  PostgreSQL version : 9.3</p>
  
  <pre><code>COALESCE(LastLoginTimestamp,'')
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>invalid input syntax for type timestamp with time zone: ""
  </code></pre>
  
  <p>What I need to do in order to have default/empty value if LastLoginTimestamp is null.</p>