title: Using alias name another columns list value
body: <p>I have table which looks like this</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>A</th>
  <th>B</th>
  <th>c</th>
  <th>list</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>d2</td>
  <td>d3</td>
  <td>d4</td>
  <td>[key1,key2,key3]</td>
  </tr>
  <tr>
  <td>d21</td>
  <td>d31</td>
  <td>d5</td>
  <td>[key1,key2,key4]</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I want to get the key name from the array list by indexing and assign the columnn name as alias,
  so my final output table sould looks like this</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>key1</th>
  <th>key2</th>
  <th>key3</th>
  <th>list</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>d2</td>
  <td>d3</td>
  <td>d4</td>
  <td>[key1,key2,key3]</td>
  </tr>
  <tr>
  <td>d21</td>
  <td>d31</td>
  <td>d5</td>
  <td>[key1,key2,key4]</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I know its silly but i have tried this</p>
  <pre><code>select 
  A as array[0],
  B as array[1],
  C as array[2]
  from table
  </code></pre>
  <p>obviously it didn't work , i am pretty new to SQL ( I am using clickhouse ) , is there a way to do it? , thank you</p>