title: I'm getting an error when I try to find the average
body: <pre><code>SELECT AVG(product.product_price) 
    from product
       , customer
       , orderline
       , orders 
   WHERE product.product_id = orderline.product_id 
     AND orderline.order_id = orders.order_id 
     and = orders.cust_id = customer.cust_id 
     AND customer.city LIKE 'Tuscon'
   group 
      by product.name
  </code></pre>
  <p>I'm trying to find the average price of a product ordered by a customer in tucson</p>