title: Solve QUERY for showing TOP 5 selling Products
body: <p>I have a table of <code>Customer_Invoice</code> having columns of <code>item_name</code> and <code>Quantity</code>. I want to show the top 5 Items on the specific item &amp; Item Quantity Sold in Descending order i-e if the number of item A is sold 5 and the number of item B is sold 3 then Item A should be on Top and and item B will be on 2nd number.</p>
  
  <pre><code>|  ITEMCODE | QUANTITY |
  ------------------------
  |     kb434 |        1 |
  | A4tech123 |        4 |
  |   HDD40GB |        4 |
  |    Cell12 |        4 |
  |    Icd123 |        2 |
  | A4tech123 |        6 |
  </code></pre>
  
  <p>In the above diagram I want <code>A4tech123</code> on 1st no <code>HDD40GB</code> on 2nd No, <code>Cell12</code> on third no and so on. </p>