title: DB2 Comma Separated Output by Groups
body: <p>Is there a built in function for comma separated column values in <code>DB2 SQL</code>?</p>
  
  <p><strong>Example:</strong> If there are columns with an <code>ID</code> and it has 3 rows with the same <code>ID</code> but have three different roles, the data should be concatenated with a comma.</p>
  
  <pre><code>ID   | Role
  ------------
  4555 | 2
  4555 | 3
  4555 | 4
  </code></pre>
  
  <p>The output should look like the following, per row:</p>
  
  <p><code>4555 2,3,4</code></p>