title: Sort Firebase data in ascending/Descending Order
body: <p>I'm Working with stock management project and my client want sales of stock in ascending and descending order.</p>
  
  <p>I have Stock structure as below</p>
  
  <p><a href="https://i.stack.imgur.com/QP9nf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QP9nf.png" alt="enter image description here"></a></p>
  
  <p>I want to sort the data as per the sales of the product.</p>
  
  <p>NOTE: There are thousands of products in this database, so downloading and then sorting the data isn't good idea. I believe this will slow down the process.</p>