title: Replace NULL using a function
body: <p>Is there any function to replace NULL or empty space with special character in hive? when I execute the below statement it returns a <strong>semantic exception stating trim works only on string/nvarchar</strong></p>
  
  <pre><code>CASE
   WHEN TRIM(q.address) = '' OR q.address IS NULL THEN '?'
   ELSE q.address END as address
  </code></pre>
  
  <p>Please help.</p>