title: Get field name in SQL query with DISTINCT and UNION
body: <p>I have following query:</p>
  
  <pre><code>SELECT DISTINCT(uniq)
  FROM
  (
      SELECT sex AS uniq FROM type4
      UNION
      SELECT fason AS uniq FROM type4
      UNION
      SELECT color AS uniq FROM type4
      UNION
      SELECT size AS uniq FROM type4
  ) AS Temp
  </code></pre>
  
  <p>It works almost well, it returns:</p>
  
  <pre><code>[uniq] =&gt; some unique value
  </code></pre>
  
  <p>Is it possible to know which column this unique value was from?
  I mean something like this:</p>
  
  <pre><code>[uniq] =&gt; some unique value
  [from] =&gt; size
  </code></pre>
  
  <p>How can I do this?</p>