title: YouTube Analytics - when to stop querying?
body: <p>A quick overview of what my application is doing:</p>
  
  <ol>
  <li>A customer authenticates their Google account via OAuth.</li>
  <li>I retrieve their access and refresh tokens and store them for use</li>
  <li>I make a YouTube Analytics report query for basic metrics such as views, comments, etc..  I query starting from today, and go backwards in time.</li>
  </ol>
  
  <p>My question is: How do I know when to stop querying?  </p>
  
  <p>The API doesn't appear to return any errors even if I specify a date from 1980.  The API does seem to return no results in that the "rows" field is not present:</p>
  
  <p>{"kind":"youtubeAnalytics#resultTable","columnHeaders":[{"name":"day","columnType":"DIMENSION","dataType":"STRING"},{"name":"views","columnType":"METRIC","dataType":"INTEGER"}]}</p>
  
  <p>Is it reliable for me to stop querying if the API returns a result like this where the "rows" field is not-present?  My concern is if the customer doesn't have any data for a certain period, and the API returns this type of result (missing "rows" field), is it possible that the customer still has data prior to his time period?  Thus I should continue querying backwards?  How do I know when to stop?</p>