title: Query to find the customer with highest amount of total purchases
body: <p>My relationship schema looks something like this :</p>
  
  <p><a href="https://i.stack.imgur.com/ofJMN.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ofJMN.jpg" alt="enter image description here"></a></p>
  
  <p>Now I am trying to write a SQL query to <em>find the customer who has the <strong>highest total amount of purchases</strong> in the year 2016</em>. I want to know the customer name and the total amount of purchases.</p>
  
  <pre><code>Select Customer_name, TotalAmountOfAllHisPurchases from ...
  </code></pre>
  
  <p>I cannot think of a neat way of doing this. Anyone who can help me get started on this please?</p>