title: SQL query - filter out field containing only spaces
body: <p>I need to write a sql query that filters out rows that have a changing number of spaces in a field. For example, I have this query</p>
  
  <pre><code>   SELECT MEMO_SYSTEM_TXT
     FROM [EE].[dbo].[EE_Billing_Memo]
     where MEMO_SYSTEM_TXT is not null and MEMO_SYSTEM_TXT &lt;&gt; '' and MEMO_SYSTEM_TXT &lt;&gt;  ' '
  </code></pre>
  
  <p>I found out that the field MEMO_SYSTEM_TXT  might contain different number of spaces, so my restrictions are not sufficient. Anyone have a robust where cluase that will filter out all spaces at once ?</p>