title: How to fill in missing date strings in SQL Select statement?
body: <p>I have a table that looks like this:</p>
  
  <pre><code>     ds     |  num_teams
  --------------------------
   2020-01-08 |     13
   2020-01-05 |      9
   2020-01-02 |     11
   2019-12-31 |      8
  </code></pre>
  
  <p>But I need to fill in the missing date strings in a way that's consistent with increases / decreases, resulting in something like this:</p>
  
  <pre><code>     ds     |  num_teams
  --------------------------
   2020-01-08 |     13
   2020-01-07 |      9
   2020-01-06 |      9
   2020-01-05 |      9
   2020-01-04 |     11
   2020-01-03 |     11
   2020-01-02 |     11
   2020-01-01 |      8
   2019-12-31 |      8
  </code></pre>
  
  <p>This is also a read-only database so it has to be done in a SQL <code>SELECT</code> statement, so I'm thinking it might be possible using <code>OVER()</code> somehow?</p>