I created two classes:

@Entity
@Inheritance( strategy = InheritanceType.JOINED )
public class Parent implements Serializable {

 @Id
 @GeneratedValue
 private Long id;

 @Column( unique = true, nullable = false )
 private String name;
 ...
}

@Entity
public class Child extends Parent {

 @Column
 private String dsc;
 ...
}

Saving, retrieve, updating of Parent class objects is perfect.
But I can't save Child class objects.
It is interesting to know that after writing Parent class object both
tables are created.
Please, help me in this dummy situation.