title: set a map to a parameterclass in iBatis
body: <p>what's the difference between setting a map and setting an object to a parameterClass in iBatis?</p>
  
  <p>means,</p>
  
  <pre><code>&lt;update id="update" parameterClass="map"&gt;
      UPDATE city 
      SET province_id = #province_id#
      WHERE id = #id# 
  &lt;/update&gt;
  </code></pre>
  
  <p>and</p>
  
  <pre><code>&lt;update id="update" parameterClass="City"&gt;
      UPDATE city 
      SET province_id = #province_id#
      WHERE id = #id# 
  &lt;/update&gt;
  </code></pre>
  
  <p>?</p>
  
  <p>I could not find any difference when I tested both.</p>
  
  <p>I really want to set all with "map", but scared ...</p>