title: Fetching one to many relationship from same table
body: <p>I have to pull one to many relationship data from the same table.
  The structure of the table is like </p>
  
  <pre><code>____________________________________
  | CUSTOMER_ID | SUBSCRIPTION_NAME |
  -------------------------------------
  |  1          |  ABC              |
  |  1          |  TNT              |
  |  1          |  AMC              |
  |  2          |  ABC              |
  |  2          |  USA              |
  |  3          |  TNT              |
  |  3          |  AMC              |
  -------------------------------------
  </code></pre>
  
  <p>I would like to get the output like </p>
  
  <pre><code>    | CUSTOMER_ID   |  SUBSCRIPTION_NAME |
      |  1            |  ABC,TNT,AMC       |
      |  2            |  ABC,USA           |
      |  3            |  TNT,AMC           |
  </code></pre>