title: Return all possible combinations of values on columns in SQL
body: <p>How do I return a list of all combinations of values in 2 columns so they are new rows in T-SQL?</p>
  
  <p>e.g.</p>
  
  <pre><code>Col1, Col2
  ----  ----
  1     2
  1     4
  1     5
  </code></pre>
  
  <p>and turn this into all combinations:</p>
  
  <pre><code>1     2
  1     4
  1     5
  2     4
  2     5
  4     5
  </code></pre>