<changelog xmlns="http://www.codesynthesis.com/xmlns/odb/changelog" database="mysql" version="1"> <changeset version="2"> <alter-table name="object"> <alter-column name="num" null="true"/> </alter-table> </changeset> <model version="1"> <table name="object" options="ENGINE=InnoDB" kind="object"> <column name="id" type="INT" null="false"/> <column name="num" type="INT" null="false"/> <primary-key auto="true"> <column name="id"/> </primary-key> </table> </model> </changelog>