title: Why when unnesting two or more variables in BigQuery do I get no results?
body: <p>I'm looking at the particular actions of one visitor on our site just to gain an understanding of how some data is collected and how to pull the data that I need.  Basically specific promotions are fired when a visitor sees certain sections of our site and I wanted to see if this data is being collected.</p>
  
  <p>I've run the following code to identify the pages a visitor sees and the events their session fires:</p>
  
  <pre><code>select fullvisitorid, visitid, date, hitnumber, type, page.pagepath, 
  eventinfo.eventcategory, eventinfo.eventlabel, eventinfo.eventaction
  from `big-query-156009.xxxxxx.ga_sessions_*` t, t.hits as hits
  where _table_suffix between "20170511" and "20170511"
  and fullvisitorid = 'xxxxxxxxxxxxxxxxxxxxxxxxxx'
  and visitid = xxxxxxxxx
  order by hitnumber
  </code></pre>
  
  <p>This works perfectly fine and I can see the journey of the visitor.  I also want to pull in </p>
  
  <pre><code>hits.promotion.promoid, 
  hits.promotion.promoname, 
  hits.promotion.promocreative, 
  hits.promotion.promoposition, 
  hits.promotionactioninfo.promoisview,
  hits.promotionactioninfo.promoisclick
  </code></pre>
  
  <p>I've tried this using the following code:</p>
  
  <pre><code>select fullvisitorid, 
  visitid, 
  date, 
  hitnumber, 
  type, 
  page.pagepath, 
  eventinfo.eventcategory, 
  eventinfo.eventlabel, 
  eventinfo.eventaction, 
  promotion.promoId, 
  promotion.promoname, 
  promotion.promocreative, 
  promotion.promoposition,
  promotionactioninfo.promoIsView,
  promotionactioninfo.promoIsclick
  from `big-query-156009.xxxxxx.ga_sessions_*` t, t.hits as hits,
  hits.promotion as promotion
  where _table_suffix between "20170511" and "20170511"
  and fullvisitorid = 'xxxxxxxxxxxxxxxxxxxxxxxxxx'
  and visitid = xxxxxxxxx
  order by hitnumber
  </code></pre>
  
  <p>however when I do this will exactly the same fullvisitorid, visitid, dates and dataset etc I get no results.  No errors or anything just no results.</p>
  
  <p>I don't fully understanding nesting so I'm assuming I'm just missing something simple.</p>
  
  <p>Is there any way around this to pull all this data in one query or do I need to do sub-queries?</p>
  
  <p>Thank you</p>