title: How does greater than comparison operator on NVARCHAR field works in SQL Server?
body: <p>I was reviewing a code in order to rewrite the logic for migration purpose and I encountered ">" operator used on NVARCHAR column.</p>
  
  <p>Sample:</p>
  
  <pre><code>SELECT COL_A, COL_B FROM TBL WHERE COL_C &gt; ''
  </code></pre>
  
  <p>What does it really accomplish? It would make sense if it was done over numerical values.</p>
  
  <p>I have noticed that it eliminates record with white spaces in COL_C. Does it do anything more than that?</p>
  
  <p>How does this work internally? Which value does SQL Server compare it with?</p>
  
  <p>Thanks</p>