title: BigQuery Duplicate column names
body: <p>I have a query:</p>
  <pre><code>WITH DAY_WIDGET_STAT AS (
  SELECT hits.eventInfo.eventCategory, hits.eventInfo.eventAction, hits.eventInfo.eventLabel, hits.page.pagePath  
  FROM `api-open-broker.108613784.ga_sessions_20181125`, UNNEST(hits) as hits
  WHERE hits.type='EVENT' and hits.eventInfo.eventCategory LIKE &quot;%Widget%&quot;
  ),
  DAY_PAGEVIEWS_STAT AS (
  SELECT hits.page.pagePath, COUNT(*) AS pageviews
  FROM `api-open-broker.108613784.ga_sessions_20181125`,UNNEST(hits) AS hits
  WHERE hits.type = 'PAGE' GROUP BY hits.page.pagePath ORDER BY pageviews DESC)
  
  SELECT * 
  FROM DAY_WIDGET_STAT INNER JOIN DAY_PAGEVIEWS_STAT ON DAY_WIDGET_STAT.pagePath=DAY_PAGEVIEWS_STAT.pagePath
  LIMIT 10
  </code></pre>
  <p>Which gives me &quot;Duplicate column names in the result are not supported. Found duplicate(s): pagePath&quot;.
  Why?
  Table DAY_WIDGET_STAT:
  <a href="https://i.stack.imgur.com/9dEZi.png" rel="nofollow noreferrer">Look</a>
  DAY_PAGEVIEWS_STAT:
  <a href="https://i.stack.imgur.com/aMwHj.png" rel="nofollow noreferrer">Look</a></p>