title: SQL set operation with different number of columns in each set
body: <p>Let say I have set 1:</p>
  
  <pre><code>1   30  60
  2   45  90
  3   120 240
  4   30  60
  5   20  40
  </code></pre>
  
  <p>and set 2</p>
  
  <pre><code>30  60
  20  40
  </code></pre>
  
  <p>I would like to do some sort of union where I only keep rows 1,4,5 from set 1 because the latter 2 columns of set 1 can be found in set 2.</p>
  
  <p>My problem is that set based operations insist on the same numnber of <strong>columns</strong>.</p>
  
  <p>I've thought of concatenating the columns contents, but it feels dirty to me.</p>
  
  <p>Is there a 'proper' way to accomplish this?</p>
  
  <p><strong>I'm on SQL Server 2008 R2</strong></p>
  
  <p>In the end, I would like to end up with</p>
  
  <pre><code>1   30  60
  4   30  60
  5   20  40
  </code></pre>
  
  <p><strong>CLEARLY I need to go sleep as a simple join on 2 columns worked.... Thanks!</strong></p>