title: Sql select group by and string concat
body: <p>i have a table like this</p>
  
  <pre><code>ID  NAME    Amount
  1   cal     100
  2   cal     200
  3   cal     300
  4   cal     400
  1   ser     500
  2   ser     600
  5   ser     700
  </code></pre>
  
  <p>i want to write a select query so that i wil get the resul like this</p>
  
  <pre><code>ID  NAME            Amount
  1   cal and ser     600
  2   cal and ser     800
  3   cal             300
  4   cal             400
  5   ser             700
  </code></pre>
  
  <p>here i need to group by id and sum of amount and concat the string name with same id and differnet name</p>