title: In a specific mySQL row find the column with the matching value
body: <p>In my table I need to search specific columns in a specific row to find which column contains the value I define.</p>
  
  <p>For example in my table</p>
  
  <pre><code>ID | Col1 | Col2 | Col3 | Col4 | Col5 | Col6
  --------------------------------------------
  1  | A    | B    | C    | C    | B    | A
  2  | C    | B    | A    | A    | C    | B
  3  | B    | A    | C    | B    | A    | C
  </code></pre>
  
  <p>I need a query to search <strong>columns 4, 5 and 6</strong> in <strong>Row 2</strong> and tell me in which column value B occurs (Col6).</p>