title: Expand table with key column to full table with null values - SQL Server select query
body: <p>I have a clean table, and I want to expand it so that in rows without values I get NULL with a SQL <code>select</code> query.</p>
  <p>For example this is table A:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>key</th>
  <th>text</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>t1</td>
  </tr>
  <tr>
  <td>2</td>
  <td>t2</td>
  </tr>
  <tr>
  <td>5</td>
  <td>t3</td>
  </tr>
  <tr>
  <td>7</td>
  <td>t4</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I'm trying to get this output:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>key</th>
  <th>text</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>t1</td>
  </tr>
  <tr>
  <td>2</td>
  <td>t2</td>
  </tr>
  <tr>
  <td>3</td>
  <td>null</td>
  </tr>
  <tr>
  <td>4</td>
  <td>null</td>
  </tr>
  <tr>
  <td>5</td>
  <td>t3</td>
  </tr>
  <tr>
  <td>6</td>
  <td>null</td>
  </tr>
  <tr>
  <td>7</td>
  <td>t4</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Any help?</p>