title: DB - When creating another entity to let the DB at the third normal form, is it necessary to make the new entity references the old one?
body: <p>Imagine I got this table:</p>
  
  <pre><code>a                     //primary key
  b
  c
  </code></pre>
  
  <p>Where <code>a -&gt; bc</code> and <code>b -&gt; c</code>. To let this at the third normal form, I must separate it in 2 tables:</p>
  
  <pre><code>a        //primary key
  b
  </code></pre>
  
  <p>and</p>
  
  <pre><code>b        // primary key
  c
  </code></pre>
  
  <p>My question is: Do I need to make <code>b</code> at the second table references <code>b</code> at the first table?</p>