title: Convert data from wide format to long format in SQL
body: <p>I have some data in the format:</p>
  
  <pre><code>VAR1 VAR2 Score1 Score2 Score3
  A     B    1      2      3
  </code></pre>
  
  <p>I need to convert it into the format</p>
  
  <pre><code>VAR1 VAR2 VarName Value
   A     B  Score1   1
   A     B  Score2   2
   A     B  Score3   3
  </code></pre>
  
  <p>How can I do this in SQL?</p>