title: How to generate date series to occupy absent dates in google BiqQuery?
body: <p>I am trying to get daily sum of sales from a google big-query table. I used following code for that.</p>
  
  <pre><code>select Day(InvoiceDate) date, Sum(InvoiceAmount) sales from test_gmail_com.sales 
  where year(InvoiceDate) = Year(current_date()) and
  Month(InvoiceDate) = Month(current_date())
  group by date order by date
  </code></pre>
  
  <p>From the above query it gives only the sum of sales daily which were in the table. There is a chance that some days do not have any sales. For those kind of situations, I need to get the date and sum should be 0. As an example, in every month should 30 0r 31 rows with sum of sales. Examples show below. 4th day of the month does not have a sales. So its sum should be 0. </p>
  
  <pre><code>date | sales
  -----+------
  1    |   259
  -----+------
  2    |   359
  -----+------
  3    |   45
  -----+------
  4    |    0
  -----+------
  5    |  156
  </code></pre>
  
  <p>Is it possible to do in Big-query? Basically date column should be a series from 1 - 28/29/30 or 31st depending on the month of the year</p>