title: Select all columns with GROUP BY one column
body: <p>I have this table:</p>
  
  <pre><code>+----+-----+----------+
  | id | name| key      |
  +----+-----+----------+
  | 1  | foo |111000    |
  | 2  | bar |111000    |
  | 3  | foo |000111    |
  +----+-----+----------+
  </code></pre>
  
  <p>Is there a way to group by the key to get this result?</p>
  
  <pre><code>+----+-----+----------+
  | id | name| key      |
  +----+-----+----------+
  | 2  | bar |111000    |
  | 3  | foo |000111    |
  +----+-----+----------+
  </code></pre>
  
  <p>Or this result:</p>
  
  <pre><code>+----+-----+----------+
  | id | name| key      |
  +----+-----+----------+
  | 1  | foo |111000    |
  | 3  | foo |000111    |
  +----+-----+----------+
  </code></pre>
  
  <p>If I use this query:</p>
  
  <pre><code>SELECT * FROM sch.mytable GROUP BY(key);
  </code></pre>
  
  <p>This is not correct I know that, because I should group by all the columns that I need to show.</p>
  
  <p>Is there a solution for this problem?</p>