title: Concatenate certain values according to their keys using case
body: <p>I want to know how to concatenate values for certain keys. Example data:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>id</th>
  <th>key</th>
  <th>value</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>name</td>
  <td>Alex</td>
  </tr>
  <tr>
  <td>1</td>
  <td>status</td>
  <td>single</td>
  </tr>
  <tr>
  <td>1</td>
  <td>age</td>
  <td>21</td>
  </tr>
  <tr>
  <td>1</td>
  <td>income</td>
  <td>20K</td>
  </tr>
  <tr>
  <td>1</td>
  <td>hight</td>
  <td>85</td>
  </tr>
  <tr>
  <td>2</td>
  <td>name</td>
  <td>David</td>
  </tr>
  <tr>
  <td>2</td>
  <td>status</td>
  <td>single</td>
  </tr>
  <tr>
  <td>2</td>
  <td>age</td>
  <td>23</td>
  </tr>
  <tr>
  <td>2</td>
  <td>income</td>
  <td>10K</td>
  </tr>
  <tr>
  <td>2</td>
  <td>hight</td>
  <td>75</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I try to concatenate just three keys <code>Alex,21,85</code> per id.</p>
  <p>So I have something similar to that:</p>
  <pre><code>select case
      when something then null
      else concat(name.value, age.value, hight.value)
  end
  from names
  </code></pre>
  <p>So what should be in the concat in order to get this values? I don't need to show the keys but just the values combined <code>Alex,21,85</code> or <code>David,23,75</code> each time the values are different for each id so it can't be hardcoded.</p>