I discovered a weird issue when using HSQLDB as database provider for TopLink JPA. We need to explicitly include the toplink.target-database property in the persistence.xml file to make it work. <property name="toplink.target-database" value="HSQL"/> Without that, you are most likely to get this error below when you run your application: Query: DataModifyQuery() at oracle.toplink.essentials.exceptions.DatabaseException.sqlException(DatabaseException.java:304) … Caused [...]