使用休眠将值插入多个表 [英] inserting values into multiple tables using hibernate

问题描述

我有现有的表 hotel 和 hotel_services .

hotel table contains:
hotel_id
hotel_name

hotel_services contains:
hotel_id
hotel_service_name

每家酒店都可以提供多种服务，因此在我的表单中，用户可以一次输入任意数量的服务.

each hotel can offer several services, so in my form user could enter as many services as he wants at a time.

例如:

hotel name: HOTEL1
hotel_services:
1. hotel_service1
2. hotel_service2
3. hotel_service3

我的问题是我应该如何在休眠状态下将所有数据插入各自的表(即hotel和hotel_services表)中.

My question is how should i do it in hibernate in such a way that i'll be able to insert all the data into their respective tables(which are hotels and hotel_services tables).

感谢您的帮助.

推荐答案

您要描述的是Hotel和Services之间的基本OneToMany关系，映射看起来像这样(我将进行映射使用注释将其作为双向关联)

What you're describing is a basic OneToMany relation between an Hotel and Services and the mapping would look like this (I'll map it as a bidirectional association, using annotations):

@Entity
public class Hotel {
    @Id @GeneratedValue
    private Long id;

    @OneToMany(cascade=ALL, mappedBy="hotel")
    Set<Service> services = new HashSet<Service>();

    // other attributes, getters, setters

    // method to manage the bidirectional association
    public void addToServices(Service service) {
        this.services.add(service);
        service.setHotel(this);
}

@Entity
public class Service {
    @Id @GeneratedValue
    private Long id;

    @ManyToOne
    private Hotel hotel;

    // getters, setters, equals, hashCode
}

这是一个演示如何使用它的代码段:

And here is a snippet demonstrating how to use this:

SessionFactory sf = HibernateUtil.getSessionFactory(); // this is a custom utility class
Session session = sf.openSession(); 
session.beginTransaction();

Hotel hotel = new Hotel();
Service s1 = new Service();
Service s2 = new Service();
hotel.addToServices(s1);
hotel.addToServices(s2);
session.persist(hotel);

session.getTransaction().commit();
session.close();

要走得更远(因为我不会在此答案中解释所有内容)，请查看:

To go further (because I won't explain everything in this answer), have a look at:

• 《 Hibernate入门指南》 (包含具有XML映射的Native API，具有批注的Native API，JPA API)
• Hibernate Core参考指南
  • 第1章教程
  • Hibernate Getting Started Guide (covers the Native API with XML mappings, the Native API with annotations, the JPA API)
  • Hibernate Core Reference Guide
    • Chapter 1. Tutorial

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