Hi i m getting this error while using ant with hbm2ddl target.
I do attach the hbm.xml file. Im using hibernate2. Thanks guys!!!

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="com.example.hibernate">

<class name="Thing" table="thing">
<id name="id" column="id" type="java.lang.Integer">
<generator class="native"/>
</id>

<property name="name" column="name" type="java.lang.String" />
<property name="comment" column="coment" type="java.lang.String" />

<set name="todo" table="todo" >
<key column="thing_fk" />
<one-to-many class="Todo" />
</set >
</class>

</hibernate-mapping>