title: How can fill the missing dates in google BigQuery
body: <p>I want to write a chart that shows the active users in firebase</p>
  
  <p>I wrote this code </p>
  
  <pre><code>SELECT event_date, COUNT(DISTINCT user_pseudo_id) AS user_count
  FROM `mark-3314e.analytics_197261162.events_*`  
  WHERE _TABLE_SUFFIX BETWEEN FORMAT_DATE('%Y%m%d', DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY)) AND FORMAT_DATE('%Y%m%d', CURRENT_DATE())
  AND event_name = 'session_start'
  GROUP BY event_date
  ORDER BY event_date ASC
  </code></pre>
  
  <p>And this is the response </p>
  
  <pre><code>Row event_date  user_count  
  1   20190617        1
  2   20190621        3
  </code></pre>
  
  <p>is there any way to fill the missing dates between 21 and 17 with the previous data? like:</p>
  
  <pre><code>event_date  user_count  
  20190617        1
  20190618        1
  20190619        1
  20190620        1
  20190621        3
  </code></pre>