title: How to CREATE TABLE with disjoint relationship in SQL
body: <p>I am trying to create a table using a <code>disjoint subtype relationship</code>.</p>
  
  <p>For example, if the <code>Supertype</code> is furniture, and I have 3 <code>Subtypes</code> of furniture: chair, couch, and table.</p>
  
  <p>Then:</p>
  
  <pre><code>CREATE TABLE Furniture
  (order_num NUMBER(15), desc VARCHAR2(20), type VARCHAR2(10));
  </code></pre>
  
  <p>How do I make an option to pick type of chair, couch or table?</p>