title: SQL Server - Get comma separated column names which have values
body: <p>I have a table which has multiple columns (example below)</p>
  <pre><code>|Customer Id| Attr1 | Attr2 | Attr3 | Attr4 | Attr5 | Attr6 |
  |1          | 1     | 0     | 0     | 1     | 0     | 1     |
  |2          | 1     | 0     | 1     | 0     | 0     | 0     |
  |3          | 0     | 1     | 0     | 1     | 1     | 0     |
  </code></pre>
  <p>I want to fetch all customers and the attribute against which that customer has any value.</p>
  <pre><code>|Customer Id| Vals                |
  |1          | Attr1, Attr4, Attr6 |
  |2          | Attr1, Attr3        |
  |3          | Attr2, Attr4, Attr5 |
  </code></pre>
  <p>Note: Column names are known and I am not looking for dynamic query. Also query is for SQL Server 2012</p>