title: select * where not in (other table values)
body: <p>I have a <code>reserves</code> table like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>id</th>
  <th>name</th>
  <th>room_ids</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>A</td>
  <td>1,2,3</td>
  </tr>
  <tr>
  <td>2</td>
  <td>B</td>
  <td>2,3,4</td>
  </tr>
  <tr>
  <td>3</td>
  <td>B</td>
  <td>2,4,5</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>And <code>rooms</code> table like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>id</th>
  <th>room name</th>
  <th>size</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>room a</td>
  <td>1</td>
  </tr>
  <tr>
  <td>2</td>
  <td>room b</td>
  <td>2</td>
  </tr>
  <tr>
  <td>3</td>
  <td>room c</td>
  <td>1</td>
  </tr>
  <tr>
  <td>4</td>
  <td>room e</td>
  <td>3</td>
  </tr>
  <tr>
  <td>5</td>
  <td>room f</td>
  <td>1</td>
  </tr>
  <tr>
  <td>6</td>
  <td>room g</td>
  <td>2</td>
  </tr>
  <tr>
  <td>7</td>
  <td>room h</td>
  <td>2</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Is it possible to get rooms with ids not in column <code>room_ids</code> in the <code>reserves</code> table with a single query? Something like: <code>Select * from rooms where id not in (select room_ids from reserves)</code>.</p>