title: Using CASE on empty string
body: <p>I have a code that goes like this:</p>
  
  <pre><code>SELECT
  '"35933-14",' ||
  '"' || us_1.gr_UniqueName || '",' ||
  '"' || (CASE WHEN us_1.mls0_PrimaryString = '' THEN 'This is empty' 
      WHEN CAST(Length(us_1.mls0_PrimaryString) AS INT) &lt; 4 THEN ('Less than 4: '|| SUBSTR(us_1.mls0_PrimaryString,1,10000)) 
     ELSE SUBSTR(us_1.mls0_PrimaryString,1,10000)  END) || '",' ||
  '"",' ||
  '"",' ||
  '""' 
  FROM 
  us_GroupTab us_1 
  WHERE (us_1.gr_Active = 1) 
  AND (us_1.gr_PurgeState = 0) 
  AND (us_1.gr_PartitionNumber = 0)
  AND (us_1.gr_UniqueName IN ('US_HARDWARE_1', 'US_HARDWARE_2','GROUP_NULL'));
  </code></pre>
  
  <p>Basically the problem is that not all empty string is handled, some users are only inputting multiple spaces which the first case statement does not handle. Is there any way to do this, I have tried using TRIM function but it does not work.</p>
  
  <p>Thanks!</p>