1. 程式人生 > >Hibernate初學者---多對一/一對多 雙向關聯

Hibernate初學者---多對一/一對多 雙向關聯

Hibernate 版本: v5.2.10
Eclipse版本:v4.7.1
JDK版本: v1.8
MySQL版本:v5.7

POJO類一:

package com.bak.bum.union;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name = "300_user") public class Users { int id; String name; Groups groups; @ManyToOne public Groups getGroups() { return groups; } public void setGroups(Groups groups) { this.groups = groups; } @Id @GeneratedValue(strategy=GenerationType.IDENTITY) public
int getId() { return id; } public String getName() { return name; } public void setId(int id) { this.id = id; } public void setName(String name) { this.name = name; } }

POJO類二:

package com.bak.bum.union;

import java.util.HashSet;
import
java.util.Set; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; @Entity @Table(name = "300_group") public class Groups { int id; String name; Set<Users> users = new HashSet<Users>(); @Id @GeneratedValue(strategy = GenerationType.IDENTITY) public int getId() { return id; } public String getName() { return name; } @OneToMany(mappedBy="groups") public Set<Users> getUsers() { return users; } public void setId(int id) { this.id = id; } public void setName(String name) { this.name = name; } public void setUser(Set<Users> users) { this.users = users; } }

Junit-Test

package com.bak.fan.test;

import java.util.EnumSet;

import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.hibernate.tool.schema.TargetType;

public class Test {

    @org.junit.Test
    public void test() {
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();
        Metadata metadata = new MetadataSources(serviceRegistry).buildMetadata();
        SchemaExport schemaExport = new SchemaExport();
        schemaExport.create(EnumSet.of(TargetType.DATABASE), metadata);


}
}

hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>  

<!DOCTYPE hibernate-configuration PUBLIC  
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"  
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>

        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>

        <property name="connection.username">root</property>

        <property name="connection.password">shwythnn00</property>

        <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>

        <property name="show_sql">true</property>

        <property name="hibernate.format_sql">true</property>

        <property name="hibernate.hbm2ddl.auto">create</property>

        <property name=""></property>


        <mapping class="com.bak.bum.union.Groups" />
        <mapping class="com.bak.bum.union.Users" />
    </session-factory>
</hibernate-configuration>  

輸出結果

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