title: Need Average & Rolling Average in POSTGRESQL
body: <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">USER_ID</th>
  <th style="text-align: center;">DATE</th>
  <th style="text-align: right;">PRICE</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">123456</td>
  <td style="text-align: center;">2017-10-08 14:23:56</td>
  <td style="text-align: right;">7</td>
  </tr>
  <tr>
  <td style="text-align: left;">152648</td>
  <td style="text-align: center;">2017-10-15 18:14:08</td>
  <td style="text-align: right;">2</td>
  </tr>
  <tr>
  <td style="text-align: left;">958462</td>
  <td style="text-align: center;">2017-11-15 11:30:29</td>
  <td style="text-align: right;">8</td>
  </tr>
  <tr>
  <td style="text-align: left;">112233</td>
  <td style="text-align: center;">2017-11-15 11:33:11</td>
  <td style="text-align: right;">6</td>
  </tr>
  <tr>
  <td style="text-align: left;">124578</td>
  <td style="text-align: center;">2017-12-18 10:13:09</td>
  <td style="text-align: right;">6</td>
  </tr>
  <tr>
  <td style="text-align: left;">326598</td>
  <td style="text-align: center;">2017-12-20 8:56:20</td>
  <td style="text-align: right;">3</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I'm trying to get an output of average price and rolling average price by month.</p>
  <p>I can seem to get one or the other but not both.</p>
  <p>Output I want:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">Month</th>
  <th style="text-align: center;">Price</th>
  <th style="text-align: right;">Rolling Price</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">12/1/2017</td>
  <td style="text-align: center;">Number</td>
  <td style="text-align: right;">Number</td>
  </tr>
  <tr>
  <td style="text-align: left;">11/1/2017</td>
  <td style="text-align: center;">Number</td>
  <td style="text-align: right;">Number</td>
  </tr>
  </tbody>
  </table>
  </div>