secondary table per entity

One entity can have many or one secondary table . This means that the entity is saved across these secondary tables.

One secondary table with primary key for join with the primary table .

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;
import javax.persistence.SecondaryTable;
import javax.persistence.PrimaryKeyJoinColumn;

@Entity
@Table(name="PERSON")
@SecondaryTable(name="PERSON_DETAIL", 
        pkJoinColumns=@PrimaryKeyJoinColumn(name="PERSON_ID"))

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;
    }
 
    
}

 

Multiple secondary table per entity , each one has its own join column .

Code:

@Entity
@Table(name="PERSON")
 @SecondaryTables({
        @SecondaryTable(name="PERSON_DETAIL", 
            pkJoinColumns=@PrimaryKeyJoinColumn(name="PERSON_ID")),
        @SecondaryTable(name="PERSON_LOG", 
            pkJoinColumns=@PrimaryKeyJoinColumn(name="PER_ID"))
    })
 

You can specify the referenced join primary key like the following :

Code:

@Entity
@Table(name="PERSON")
@SecondaryTable(name="PERSON_DETAIL", 
        pkJoinColumns=@PrimaryKeyJoinColumn(name="PERSON_ID",referencedColumnName="ID"))