5. One-To-One relation mapping

Hibernate mappings වලදී table අතර relations, map කිරීම ඉතාම වැදගත් කාර්යයක්.

පහත දැක්වෙන්නේ One-To-One relationship එකක් map කරන ආකාරය


Employee සහ EmployeeDetail නම් class දෙක අතර සම්බන්ධය One-To-One ලෙස ගනිමු.

එනම් එක Employee කෙනෙකුට ඇත්තේ එක EmployeeDetail එකකි.
එලෙසම එක EmployeeDetail  එකක් සම්බන්ධ වන්නේ එක Employee කෙනෙක් සමඟ පමණි.


a) package abc.hibernate;

import java.sql.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="employee")
public class Employee{

@Id
@GeneratedValue
@Column(name="emp_id")
private Long empId;

@Column(name="first_name")
private String firstName;

@Column(name="last_name")
private String lastName;

@Column(name="birth_date")
private Date birth_date;

@Column(name="salary")
private double salary;

@OneToOne ( mappedBy="employee" cascade=CascadeType.ALL)
private EmployeeDetail employeeDetail;

public Employee(){
}

public Employee(String firstname, String lastname, Date birthdate, double salary){
this.firstName = firstname;
this.lastName = lastname ;
this.birthDate = birthdate ;
this.salary = salary ;
}

//Getter and Setter methods

}




b)  package abc.hibernate; 

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import javax.persistence.OneToOne;

import javax.persistence.PrimaryKeyJoinColumn;

import org.hibernate.annotations.GenericGenerator;

import org.hibernate.annotations.Parameter;

@Entity

@Table(name="employeedetail")

public class EmployeeDetail{

@Id

@Column (name="employee_id", unique=true, nullable=false)

@GeneratedValue(generator ="gen")

@GenericGenerator(name="gen", strategy="foreign", parameters=@Parameter(name="property",

                                                                                     value="employee"))

private Long employeeId;

@Column(name="street")

private String street;

@Column(name="city")

private String city;

@Column(name="state")

private String state;

@Column(name="country")

private String country;

@OneToOne

@PrimaryKeyJoinColumn

private Employee emploee ;

public EmployeeDetail(){

}

public EmployeeDetail (String street, String city, String state, String country ) {

this.street= street ;

this.city = city ;

this.state = state ;

this.country = country ;

}

//getters and setters

}