title: Empty string inserting a zero, not a null
body: <p>My insert statement looks like this:</p>
  
  <pre><code>INSERT INTO foo (bar) VALUES ('');
  </code></pre>
  
  <p>The <code>bar</code> field was created like so:</p>
  
  <pre><code>bar INT(11)
      COLLATION: (NULL)
      NULL: YES
      DEFAULT: (NULL)
  </code></pre>
  
  <p>MySQL version: 5.1.</p>
  
  <p>Shouldn’t an empty string insert a NULL? I’m not sure why I’m seeing a zero (0) being stored in the table.</p>