title: How to command google bigquery to show all row of time series data (don't omit row)
body: <p>I use an easy command for showing sales volume by store by goods item and by month in google Big Query but there are omitted month as some items were not  bought. So, I would to know is there coding for all months. <a href="https://i.stack.imgur.com/E5jQW.jpg" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>Now I try to solve the problem by build time index and item_code and cross join with store but it must be massive row if I apply this with all item code.   </p>
  
  <pre><code>SELECT bp_no,sales_month,sales_year,sum(report_qty) AS volume
  FROM my_table 
  WHERE sales_year between 2016 and 2017 and bp_no is not null and report_qty is not null 
  GROUP BY bp_no,sales_month,sales_year
  ORDER BY bp_no,sales_year, sales_month
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/rrnPa.jpg" rel="nofollow noreferrer">enter image description here</a></p>