title: error NoSuchColumnException DbUnit
body: <p>I have a table with a JSON column and when I run my tests with the dataset.</p>
  
  <pre><code>org.dbunit.dataset.NoSuchColumnException: hero.JSON - (Non-uppercase
  input column: json) in ColumnNameToIndexes cache map. Note that the map's
  column names are NOT case sensitive.
  </code></pre>
  
  <p><strong>my dataset:</strong></p>
  
  <pre><code> &lt;?xml version="1.0" encoding="UTF-8"?&gt;
   &lt;dataset&gt;
  
     &lt;hero id='000580548' json='{"id" : 1,"name" : "mySuperHero"}'/&gt;
     &lt;hero_profile id='000580548-mySuperHero' json='{"habilities": [], "stars" : 7}'/&gt;
  &lt;/dataset&gt;
  </code></pre>
  
  <p>Obs: my tables already exists in the database.</p>