title: SQL query that does not include a unique column
body: <p>So I am trying to query for rows that only have a certain matching attribute so for example:</p>
  
  <pre><code>memID     name      SSN    
  26        Dave      6    
  26        Dave      6    
  26        Dave      5    
  5         Sean      8    
  45        Ash       10    
  45        Ash       29
  </code></pre>
  
  <p>What I want for my results are all the rows except:</p>
  
  <pre><code>5     Sean     8
  </code></pre>