title: Return additional column value for MySQL Union Query
body: <p>I have two queries that get the:</p>
  
  <ol>
  <li>Most recent snow measurement (within 1 hour)</li>
  <li>And a measurement taken 24 hours ago.</li>
  </ol>
  
  <p>When I <code>UNION</code> the queries, I am expecting the two measurements to be in separate columns, but they are actually returned in separate (duplicate) rows. See output below.</p>
  
  <pre><code>SELECT snowfall.cms as now_snow, resorts.*, regions.name
  FROM  snowfall
  INNER JOIN resorts on resorts.id = snowfall.resort_id
  INNER JOIN  regions ON resorts.region_id = regions.id
  WHERE snowfall.timestamp &gt;= SUBDATE( NOW( ) , INTERVAL 1 HOUR )
  GROUP BY resorts.id
  UNION
  SELECT snowfall.cms as 24hr_snow, resorts.*, regions.name
  FROM  snowfall
  INNER JOIN resorts on resorts.id = snowfall.resort_id
  INNER JOIN  regions ON resorts.region_id = regions.id
  WHERE snowfall.timestamp &gt;= SUBDATE( NOW() , INTERVAL 1 DAY)
  GROUP BY resorts.id
  ORDER BY now_snow DESC
  </code></pre>
  
  <p>I am getting a result of:</p>
  
  <pre>now_snow | resorts.name | ...
  ========================================
  20       | The Mountain
  15       | The Mountain
  18       | The Hill
  102      | The Hill</pre>
  
  <p>But was expecting a result of:</p>
  
  <pre>now_snow | 24hr_snow | resorts.name | ...
  ========================================
  20       | 15        | The Mountain
  18       | 102       | The Hill</pre>
  
  <p>Is <code>UNION</code> correct in this scenario? How can I achieve the desired output?</p>