使用注解的Hibernate多对一映射

2024 年 8 月 29 日 | 阅读 3 分钟

在多对一映射中，多个属性可以只引用一个属性。

在此示例中，每个员工只有一个公司地址，一个地址属于多个员工。在这里，我们将使用注解执行多对一映射。

让我们看看持久化类

1) 一对一映射的持久化类

有两个持久化类 Employee.java 和 Address.java。 Employee 类包含 Address 类引用，反之亦然。

Employee.java

package com.javatpoint;
import javax.persistence.*;

@Entity
@Table(name="emp107")
public class Employee {  
	 @Id
	 @GeneratedValue(strategy=GenerationType.AUTO)	
private int employeeId;  
private String name,email;  
@ManyToOne(cascade=CascadeType.ALL)
private Address address;
public int getEmployeeId() {
	return employeeId;
}
public void setEmployeeId(int employeeId) {
	this.employeeId = employeeId;
}
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public String getEmail() {
	return email;
}
public void setEmail(String email) {
	this.email = email;
}
public Address getAddress() {
	return address;
}
public void setAddress(Address address) {
	this.address = address;
}  
}

Address.java

package com.javatpoint;

import javax.persistence.*;

@Entity
@Table(name="address107")
public class Address {
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
	private int addressId;  
	private String addressLine1,city,state,country;  
	private int pincode;  
   @OneToOne(cascade=CascadeType.ALL)
	private Employee employee;
	public int getAddressId() {
		return addressId;
	}
	public void setAddressId(int addressId) {
		this.addressId = addressId;
	}
	public String getAddressLine1() {
		return addressLine1;
	}
	public void setAddressLine1(String addressLine1) {
		this.addressLine1 = addressLine1;
	}
	public String getCity() {
		return city;
	}
	public void setCity(String city) {
		this.city = city;
	}
	public String getState() {
		return state;
	}
	public void setState(String state) {
		this.state = state;
	}
	public String getCountry() {
		return country;
	}
	public void setCountry(String country) {
		this.country = country;
	}
	public int getPincode() {
		return pincode;
	}
	public void setPincode(int pincode) {
		this.pincode = pincode;
	}
	public Employee getEmployee() {
		return employee;
	}
	public void setEmployee(Employee employee) {
		this.employee = employee;
	}  
}

2) 在 pom.xml 文件中添加项目信息和配置。

打开 pom.xml 文件并单击 source。现在，在 <dependencies>....</dependencies> 标签之间添加以下依赖项。这些依赖项用于在 Maven 项目中添加 jar 文件。

<dependency>  
    <groupId>org.hibernate</groupId>  
    <artifactId>hibernate-core</artifactId>  
    <version>5.3.1.Final</version>  
</dependency>  

<dependency>  
    <groupId>com.oracle</groupId>  
    <artifactId>ojdbc14</artifactId>  
    <version>10.2.0.4.0</version>  
</dependency>  

3) 配置文件

此文件包含有关数据库和映射文件的信息。

hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?>  
<!DOCTYPE hibernate-configuration PUBLIC  
          "-//Hibernate/Hibernate Configuration DTD 5.3//EN"  
          "http://hibernate.sourceforge.net/hibernate-configuration-5.3.dtd">  
   
<hibernate-configuration>  
  
    <session-factory>  
        <property name="hbm2ddl.auto">create</property>  
        <property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>  
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>  
        <property name="connection.username">system</property>  
        <property name="connection.password">jtp</property>  
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>  
    <mapping class="com.javatpoint.Address"/>  
    <mapping class="com.javatpoint.Employee"/>  
    </session-factory>  
  
</hibernate-configuration>  

4) 用于存储和获取数据的用户类

Store.java

package com.javatpoint;  

import org.hibernate.*;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;  
  
public class Store {  
public static void main(String[] args) {  
	
	StandardServiceRegistry ssr=new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
	Metadata meta=new MetadataSources(ssr).getMetadataBuilder().build();
	
	SessionFactory factory=meta.getSessionFactoryBuilder().build();
	Session session=factory.openSession();
	
    Transaction t=session.beginTransaction();  
      
    Employee e1=new Employee();  
    e1.setName("Ravi Malik");  
    e1.setEmail("ravi@gmail.com");  
    
    Employee e2=new Employee();
    e2.setName("Anuj Verma");
    e2.setEmail("anuj@gmail.com");
      
    Address address1=new Address();  
    address1.setAddressLine1("G-13,Sector 3");  
    address1.setCity("Noida");  
    address1.setState("UP");  
    address1.setCountry("India");  
    address1.setPincode(201301);  
      
    e1.setAddress(address1);  
    e2.setAddress(address1);

    session.persist(e1);  
    session.persist(e2);
    t.commit();  
      
    session.close();  
    System.out.println("success");  
}  
}  

输出

Hibernate Many to One Example using Annotation 1

Hibernate Many to One Example using Annotation 2

Fetch.java

package com.javatpoint;  
import java.util.Iterator;  
import java.util.List;

import javax.persistence.TypedQuery;  
import org.hibernate.Session;  
import org.hibernate.SessionFactory;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder; 
  
public class Fetch {  
public static void main(String[] args) {  
	StandardServiceRegistry ssr=new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
	Metadata meta=new MetadataSources(ssr).getMetadataBuilder().build();
	
	SessionFactory factory=meta.getSessionFactoryBuilder().build();
	Session session=factory.openSession();
      
    TypedQuery query=session.createQuery("from Employee e");  
    List<Employee> list=query.getResultList(); 
      
    Iterator<Employee> itr=list.iterator();  
    while(itr.hasNext()){  
     Employee emp=itr.next();  
     System.out.println(emp.getEmployeeId()+" "+emp.getName()+" "+emp.getEmail());  
     Address address=emp.getAddress();  
     System.out.println(address.getAddressLine1()+" "+address.getCity()+" "+  
        address.getState()+" "+address.getCountry()+" "+address.getPincode());  
    }  
  
    session.close();  
    System.out.println("success");  
}  
}  

输出

Hibernate Many to One Example using Annotation 3

输出

下载此Hibernate示例

下一个主题双向关联

← 上一个下一个 →

使用注解的Hibernate多对一映射

1) 一对一映射的持久化类

Employee.java

Address.java

2) 在 pom.xml 文件中添加项目信息和配置。

3) 配置文件

hibernate.cfg.xml

4) 用于存储和获取数据的用户类

Store.java

输出

Fetch.java

输出

输出

联系信息

关注我们

教程

面试题

在线编译器

Python

Java

.Net Framework

AI, ML and Data Science

Cloud Technology

B.Tech and MCA

Web Technology

PHP

Software Testing

Technical Interview

Java Interview

Python

Web Interview

Database Interview

B.Tech / MCA

Important Interview

Software Testing Interview

Company Interviews

Online Compilers

Multiple Choice Questions

Hibernate 教程

Hibernate 与 Eclipse

Hibernate 示例

Hibernate Log4j

继承映射

Hibernate 映射

事务管理

HQL

HCQL

命名查询

Hibernate 缓存

二级缓存

集成

其他

Hibernate 面试

使用注解的Hibernate多对一映射

1) 一对一映射的持久化类

Employee.java

Address.java

2) 在 pom.xml 文件中添加项目信息和配置。

3) 配置文件

hibernate.cfg.xml

4) 用于存储和获取数据的用户类

Store.java

输出

Fetch.java

输出

输出

相关帖子

一对多 XML

映射 Bag

多对多 XML

双向

一对多注解

映射 Set

一对一 XML

组件映射

延迟加载集合

一对一注解

订阅 Tpoint Tech

联系信息

关注我们

教程

面试题

在线编译器