I have a table Marital Status with values "single", "married", etc.
I have a table Person with marital_status_id as foreign key.
How do I mapped this one? Any help will be appreciated as I am new in Hibernate. Or I dont need this one since there isn't of a relation between Person and Marital Status but just a reference?
First of all, a marital status does not need a separate table (does it? really?). It can be handled with a single character (very efficient)
However, in your case,
@Entity
@Table(name="PERSON")
Class Person(){
@Id
@Column(name = "ID", unique = true, nullable = false, precision = 15, scale = 0)
private Long id;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="MARITAL_STATUS_ID")
MaritalStatus maritalStatus;
}
and
@Entity
@Table(name="MARITAL_STATUS")
Class MaritalStatus(){
@Id
@Column(name = "ID", unique = true, nullable = false, precision = 15, scale = 0)
private Long id;
@OneToMany(mappedBy="maritalStatus")
Set<Person> persons;
}
Marital Status should be expressed as enum in Java to exclude unnecessary joins since there are not so many options and they will never change.
Check @Enumerated(EnumType.STRING) annotation: http://docs.oracle.com/javaee/6/api/javax/persistence/Enumerated.html
You have not specified whether you insist to have one-to-one relationship or you don't care , and also if you prefer using Enum instead of a Class.
This Link provides some useful information on one-to-one mapping in hibernate, if you want to have such relationship between your tables: one-to-one exampleHowever hibernate one-to-one mapping is not much recommended, and you could simply use a one-to-many mapping just like this:
@Entity
@Table(name = "Person")
public class Person {
@Id
@GeneratedValue
int id;
@OneToMany(mappedBy = "Person", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
Private MaritalStatus;
}
@Entity
@Table(name = "MaritalStatus")
public class Person {
@Id
@GeneratedValue
int id;
@ManyToOne
Person person = new Person();
}
This approach is much simple , but you may prefer to have an Enum instead of class and map your tables using enums. That approach is a bit more difficult to implement and this post provides you all the stuff you need : Mapping enum to a table
@OneToMany and @ManyToOne annotations reversed.I would do like below
Person entity:
@Entity
@Table(schema = "Person")
public class Person {
@Id
private String id;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "marital_status_id")
private MaritalStatus maritalStatus;
}
Marital status entity:
@Entity
@Table(schema = "MaritalStatus")
public class MaritalStatus {
@Id
private String id;
@Column(name = "status")
private String status;
}
