title: Using a COUNT in a WHERE Clause to find Products Purchased By One Customer
body: <p>I have a PostgreSQL query similar to the following:</p>
  <pre><code>SELECT product, customer, COUNT(customer)
  FROM table
  WHERE COUNT (customer) = 1
  </code></pre>
  <p>I want the query to return a list of products that have only been bought by one customer. How can I do this without using a COUNT in there WHERE?</p>
  <p>Many Thanks.</p>