title: how to implement a double join in n-to-n relation in MySQL
body: <p>In my database I have cars and persons.
  Between the cars and the persons is an n-to-n 'drives'-'is driven by' relationship.</p>
  
  <p>I would like to query the database to get a list of all the cars that are driven by a specific person (say 'john') and that are also driven by other persons. I would like the query to show per car how many (other) persons are driving it.</p>
  
  <p>The above is a simplification of my actual problem. For extra reference;
  Cars are typically driven by 1 to 4 persons, but 1 person drives up to 5000 cars</p>
  
  <p>Is it possible to do this in a single query, and if so, how?</p>
  
  <p>greetings,</p>
  
  <p>Coen</p>