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Hibernate一对多保存思考题 Java框架

Hibernate一对多保存思考题 Java框架

作者: 林万程 | 来源:发表于2017-10-11 23:25 被阅读97次

出道题给大家玩玩

public class Customer {
    private Long id;
    private String name;
    private Set<Linkman> linkmans = new HashSet<Linkman>(0); // 一对多
}
public class Linkman implements java.io.Serializable{
    private Long id;
    private String name;
    private Customer customer; // 多对一    
}
package test.java;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.junit.Test;

import util.HibernateUtils;
import entity.Customer;
import entity.Linkman;

/**
 * 请说明以下语句各显示发送多少条SQL语句,是否报错,外键是否保存
 * 并说明在Customer设置不维护外键inverse="true"的情况下的结果
 */
public class SaveTest {
    @Test
    public void saveTest() throws Exception {
        // 1.多对一先存多:
        saveCommand("lc", "sl", "sc");
        // 2.多对一先存一:
        saveCommand("lc", "sc", "sl");
        // 3.一对多先存多:
        saveCommand("cl", "sl", "sc");
        // 4.一对多先存一:
        saveCommand("cl", "sc", "sl");
        // 5.互关联先存多:
        saveCommand("cl", "lc", "sl", "sc");
        // 6.互关联先存一:
        saveCommand("cl", "lc", "sc", "sl");
        // 7.多对一只存多:
        saveCommand("lc", "sl");
        // 8.多对一只存一:
        saveCommand("lc", "sc");
        // 9.一对多只存多:
        saveCommand("cl", "sl");
        // 10.一对多只存一:
        saveCommand("cl", "sc");
        // 11.互关联只存多:
        saveCommand("cl", "lc", "sl");
        // 12.互关联只存一:
        saveCommand("cl", "lc", "sc");
    }

    public void saveCommand(String... commands) {
        Session session = HibernateUtils.getCurrentSession();
        Transaction tx = session.beginTransaction();
        Customer customer = new Customer();
        customer.setName("客户");
        Linkman linkman1 = new Linkman();
        linkman1.setName("联系人1");
        Linkman linkman2 = new Linkman();
        linkman2.setName("联系人2");

        for (String command : commands) {
            switch (command) {
            case "lc": // 多对一
                linkman1.setCustomer(customer);
                break;
            case "cl": // 一对多
                customer.getLinkmans().add(linkman1);
                break;
            case "sc": // 存一
                session.save(customer);
                break;
            case "sl": // 存多
                session.save(linkman1);
                break;
            default:
                break;
            }
            System.out.println(" " + customer + "\n " + linkman1);
        }
        System.out.println("提交:");
        tx.commit();
        System.out.println(" " + customer + "\n " + linkman1);
    }
}

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