title: String_agg for SQL Server before 2017
body: <p>Can anyone help me make this query work for SQL Server 2014?</p>
  <p>This is working on Postgresql and probably on SQL Server 2017. On Oracle it is <code>listagg</code> instead of <code>string_agg</code>.</p>
  <p>Here is the SQL:</p>
  <pre><code>select 
      string_agg(t.id,',') AS id
  from 
      Table t
  </code></pre>
  <p>I checked on the site some xml option should be used but I could not understand it.</p>