Join Column by Primary Key

Sat Apr 17, 2010 9:48 pm

The following code represents a one-to-one relation between person table and bed table (" Actually i want to sleep now

") . The primary key of person is used as the key of bed entity .

Person entity class . (Notice the annotation of one-to-one )

Code:: package com.codemiles.jpa; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.OneToOne; import javax.persistence.Table; @Entity @Table(name="PERSON") public class Person implements java.io.Serializable{ /** * */ private static final long serialVersionUID = 1L; @Id private String Id; private String name; private Date birthday; private String gender; @OneToOne(mappedBy="person") private Bed bed; public String getId() { return Id; } public void setId(String id) { Id = id; } @Column(name="NAME") public String getName() { return name; } public void setName(String name) { this.name = name; } @Column(name="BIRTHDAT") public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } @Column(name="GENDER") public String getGender() { return gender; } public void setGender(String gender) { this.gender = gender; } public void setBed(Bed bed) { this.bed = bed; } public Bed getBed() { return bed; } }

@PrimaryKeyJoinColumn annotation is used to specify the relation .

Code:: package com.codemiles.jpa; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.OneToOne; import javax.persistence.PrimaryKeyJoinColumn; import javax.persistence.Table; @Entity @Table(name="BED") public class Bed implements java.io.Serializable{ /** * */ private static final long serialVersionUID = 1L; @Id private String Id; private String type; private Date production_date; private String width; private String height; @OneToOne @PrimaryKeyJoinColumn private Person person; public String getId() { return Id; } public void setId(String id) { Id = id; } @Column(name="TYPE") public String getType() { return type; } public void setType(String type) { this.type = type; } @Column(name="PRODUCTION") public Date getProduction_date() { return production_date; } public void setProduction_date(Date production_date) { this.production_date = production_date; } @Column(name="WIDTH") public String getWidth() { return width; } public void setWidth(String width) { this.width = width; } @Column(name="HEIGHT") public String getHeight() { return height; } public void setHeight(String height) { this.height = height; } public void setPerson(Person person) { this.person = person; } public Person getPerson() { return person; } }