ORA-00904: : invalid identifier Issue with Hibernate Dependent objects program

I am working on a simple hibernate dependent objects program using `Oracle` as my database. Here are my POJO classes: Person ``` public class Person { private java.util.Date birthday; private Name name; private String key; ... getters & setters ... } ``` Name ``` public class Name { char initial; String first; String last; ... getters & setters ... } ``` Hibernate mapping file: person.hbm.xml ``` <hibernate-mapping> <class name="Person" table="person1"> <id name="Key" column="pid" type="string"> <generator class="uuid" /> </id> <property name="birthday" type="date" /> <component name="Name" class="Name"> <!-- class attribute optional --> <property name="initial" /> <property name="first" /> <property name="last" /> </component> </class> </hibernate-mapping> ``` I have set the `hbm2ddl.auto` property as `update` in my `hibernate.cfg.xml` file so tables are created when I execute my program. Here is my simple program that tries to save an instance of Person object: ``` public class Program { public static void main(String[] args) { Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); Name name = new Name(); name.setFirst("First"); name.setLast("First"); name.setInitial('I'); Person person = new Person(); person.setBirthday(new Date()); person.setName(name); session.save(person); session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); } } ``` Now when I am executing this program, I am getting error while creation of table itself: 15:20:45,376 ERROR SchemaUpdate:235 - HHH000388: Unsuccessful: create table person1 (pid varchar2(255) not null, birthday date, initial char(1), first varchar2(255), last varchar2(255), primary key (pid)) 15:20:45,376 ERROR SchemaUpdate:236 - ORA-00904: : invalid identifier I tried changing names of my properties in `Person` class as well as `Name` class but still I am facing this issue. Please let me know where I am doing mistake?