title: What are the keys for a supporting / intersection entity?
body: <p>If we have </p>
  
  <pre><code> ____________           /      \             ____________
  |   Person   |-------- /        \    ------&gt;|   Location |
  |____________|        /  BornIn  \          |_____________
                        \          /
                         \        /
                          \      /
  
  Person(SSN, first name, last name)
  BornIn(..)
  Location(City, Country, zip-code)
  </code></pre>
  
  <p>where <strong>SSN</strong> is the key for <code>Person</code>, and <code>Location is</code> determined by all three attributes.</p>
  
  <p>For a weak entity, the key is made up of all attributes of the weak entity + the primary keys (or foreign key) of the owner entity. </p>
  
  <ol>
  <li>What is/are the key(s) of <code>BornIn</code>? </li>
  <li>What is/are the key(s) of a weak supporting entity? </li>
  </ol>
  
  <p>I just can't find the answers online yet. This is not homework. I am learning database design....</p>
  
  <p>My bad. It's Many to One relationship. </p>