title: Alternative to CASE WHEN?
body: <p>I have a table in SQL where the results look something like:</p>
  
  <pre><code>Number  |  Name     |  Name 2 
  1       |  John     |  Derek  
  1       |  John     |  NULL   
  2       |  Jane     |  Louise 
  2       |  Jane     |  NULL   
  3       |  Michael  |  Mark   
  3       |  Michael  |  NULL    
  4       |  Sara     |  Paul    
  4       |  Sara     |  NULL    
  </code></pre>
  
  <p>I want a way to say that if Number=1, return Name 2 in new column Name 3, so that the results would look like:</p>
  
  <pre><code>Number  |  Name     |  Name 2  |  Name 3
  1       |  John     |  Derek   |  Derek
  1       |  John     |  NULL    |  Derek
  2       |  Jane     |  Louise  |  Louise
  2       |  Jane     |  NULL    |  Louise
  3       |  Michael  |  Mark    |  Mark
  3       |  Michael  |  NULL    |  Mark
  4       |  Sara     |  Paul    |  Paul
  4       |  Sara     |  NULL    |  Paul
  </code></pre>
  
  <p>The problem is that I can't say if Number=1, return Name 2 in Name 3, because my table has >100,000 records. I need it to do it automatically. More like "if Number is the same, return Name 2 in Name 3." I've tried to use a CASE statement but haven't been able to figure it out. Is there any way to do this?</p>