title: What triggers ConstraintException when loading DataSet?
body: <p>How can I find out which column and value is violating the constraint? The exception message isn't helpful at all:</p>
  
  <blockquote>
    <p>Failed to enable constraints. One or
    more rows contain values violating
    non-null, unique, or foreign-key
    constraints.</p>
  </blockquote>