title: MYSQL select data with predefined values if date not exist in same table
body: <p>I have resutl sql with syntax:</p>
  <pre><code>SELECT AreaName, Date, Total
  FROM table
  GROUP BY AreaName, Date
  </code></pre>
  <p>Here Result:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>AreaName</th>
  <th>Date</th>
  <th>Total</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>London</td>
  <td>2021-01-01</td>
  <td>2</td>
  </tr>
  <tr>
  <td>Paris</td>
  <td>2021-01-01</td>
  <td>3</td>
  </tr>
  <tr>
  <td>London</td>
  <td>2021-02-01</td>
  <td>4</td>
  </tr>
  <tr>
  <td>Beijing</td>
  <td>2021-02-01</td>
  <td>5</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>But I want include AreaName if date data not exist with value Total 0. Like here:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>AreaName</th>
  <th>Date</th>
  <th>Total</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>London</td>
  <td>2021-01-01</td>
  <td>2</td>
  </tr>
  <tr>
  <td>Paris</td>
  <td>2021-01-01</td>
  <td>3</td>
  </tr>
  <tr>
  <td>Beijing</td>
  <td>2021-01-01</td>
  <td>0</td>
  </tr>
  <tr>
  <td>London</td>
  <td>2021-02-01</td>
  <td>4</td>
  </tr>
  <tr>
  <td>Paris</td>
  <td>2021-02-01</td>
  <td>0</td>
  </tr>
  <tr>
  <td>Beijing</td>
  <td>2021-02-01</td>
  <td>5</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Any Advice ?</p>