title: select number of times result of one query occurs in another table
body: <p>let's say I have two tables:</p>
  
  <pre><code>USERS:
  User_Id
  Hansen
  Nilsen
  Jensen
  Bob
  </code></pre>
  
  <p>and</p>
  
  <pre><code>ORDERS:
  O_Id    OrderDate   OrderPrice  Customer
  1       2008/11/12  1000        Hansen
  2       2008/10/23  1600        Nilsen
  3       2008/09/02  700         Hansen
  4       2008/09/03  300         Hansen
  5       2008/08/30  2000        Jensen
  6       2008/10/04  100         Nilsen
  </code></pre>
  
  <p>I want to do a query to show how many times a customer ordered, so it'd look like:</p>
  
  <pre><code>Customer    Orders
  Hansen      3
  Nilsen      2
  Jensen      1
  Bob         0
  </code></pre>
  
  <p>I know I have to use the COUNT function, but I am at a loss as to how to finish this query off...</p>