title: Getting the average price of products in a category
body: <p>My database looks like:</p>
  
  <pre><code>Table - Products
  products_id 
  products_price 
  
  Table - Products_to_Categories
  categories_id
  products_id 
  
  Table - Products_Descriptions
  products_name
  
  Table - Categories_Descriptions
  categories_name
  </code></pre>
  
  <p>There's a bunch other columns but these are the ones I need.</p>
  
  <p>I want to select all the above columns but I also want to end up with an average product price <strong>for each category</strong> </p>
  
  <p>I know it's probably going to include the AVG() function but I've tried a bunch of different queries (I'm a bit of a learner) and I'm buggered if I can figure out something that works. Is it even possible to do this with just one query? I just can't get my head around it at the moment.</p>
  
  <p>Any help would be most gratefully received. :(</p>