title: What the best way to model a many to many relationship
body: <p>I'm trying to understand the best way to model the following relationship:</p>
  
  <p>I have a table named <code>Contact</code> that has records of contacts uniquely identified using a <code>serial</code> field and other fields like <code>name</code>, <code>phone</code>, <code>address</code> and so on.</p>
  
  <p>I also have a table named <code>ProductInfo</code> that has several fields including three fields named <code>Author</code>, <code>Distributor</code> and <code>PointOfContact</code> that each can have 1..n contacts from table <code>Contact</code>. So, in this way, this means that I can have two authors, 3 distributors and 1 point of contact to the same product.</p>
  
  <p>I was thinking of storing this info in <code>ProductInfo</code> table with arrays of <code>contact_id</code> in each field, but this seems not to be the best approach. </p>
  
  <p>Can you tell me what should I do?</p>