hibernate一对多,细节讲解

1.一对多

　1).首先创建两个实体类studeninfo.java跟studentxxb.java

　　　　1)studentinfo.java表如图:

package model;

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

public class studentinfo {
	private Integer id;
	private String name;
	private String aihao;
	private Date sjina;
	private Set<studentxxb> studentxxbs=new HashSet<>();
	public studentinfo() {
		super();
	}
	public studentinfo(Integer id, String name, String aihao, Date sjina, Set<studentxxb> studentxxbs) {
		super();
		this.id = id;
		this.name = name;
		this.aihao = aihao;
		this.sjina = sjina;
		this.studentxxbs = studentxxbs;
	}
	@Override
	public String toString() {
		return "studentinfo [id=" + id + ", name=" + name + ", aihao=" + aihao + ", sjina=" + sjina + ", studentxxbs="
				+ studentxxbs + "]";
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getAihao() {
		return aihao;
	}
	public void setAihao(String aihao) {
		this.aihao = aihao;
	}
	public Date getSjina() {
		return sjina;
	}
	public void setSjina(Date sjina) {
		this.sjina = sjina;
	}
	public Set<studentxxb> getStudentxxbs() {
		return studentxxbs;
	}
	public void setStudentxxbs(Set<studentxxb> studentxxbs) {
		this.studentxxbs = studentxxbs;
	}
}

　　

　　　2)stdentxxb.java如下图:

　　　　

package model;

import java.util.Date;

public class studentxxb {
	private Integer id;
	private String dhua;
	private String diz;
	private studentinfo studentinfos;
	public studentxxb() {
		super();
	}
	public studentxxb(Integer id, String dhua, String diz, studentinfo studentinfos) {
		super();
		this.id = id;
		this.dhua = dhua;
		this.diz = diz;
		this.studentinfos = studentinfos;
	}
	@Override
	public String toString() {
		return "studentxxb [id=" + id + ", dhua=" + dhua + ", diz=" + diz + ", studentinfos=" + studentinfos + "]";
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getDhua() {
		return dhua;
	}
	public void setDhua(String dhua) {
		this.dhua = dhua;
	}
	public String getDiz() {
		return diz;
	}
	public void setDiz(String diz) {
		this.diz = diz;
	}
	public studentinfo getStudentinfos() {
		return studentinfos;
	}
	public void setStudentinfos(studentinfo studentinfos) {
		this.studentinfos = studentinfos;
	}
}

　　2).两个实体类创建好了，接下来配置两个实体类的hbm.xml文件

　　　　　　1).实体类studentinfo.java的配置(studentinfp-mapping.hbm.xml)如图：

　　　　　　　　

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
		"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
		"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class name="model.studentinfo" table="studentinfo">
		<id name="id" column="id">
			<generator class="native"></generator>
		</id>
		<property name="name" column="name"></property>
		<property name="aihao" column="aihao"></property>
		<property name="sjina" column="sjina"></property>
		<set name="studentxxbs">
			<key>
				<column name="student_xxbs"></column>
			</key>
		<one-to-many class="model.studentxxb"/>
		</set>
	</class>

</hibernate-mapping>

　　

　　　　　　2).　实体类studentxxb.java的配置(studentxxb-mapping.hbm.xml)如图：

　　　　　　　　　　

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
		"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
		"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class name="model.studentxxb" table="studentxxb">
		<id name="id" column="id">
			<generator class="native"></generator>
		</id>
		<property name="dhua" column="dhua"></property>
		<property name="diz" column="diz"></property>
　　　　　　　　　　　　
		<many-to-one name="studentinfos" class="model.studentinfo" column="student_infos"></many-to-one>

	</class>

</hibernate-mapping>

　　3)接下来配置cfg.xml文件这里命名为(hibernate.cfg.xml):

　　　　

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
		"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
		"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class name="model.studentinfo" table="studentinfo">
		<id name="id" column="id">
			<generator class="native"></generator>
		</id>
		<property name="name" column="name"></property>
		<property name="aihao" column="aihao"></property>
		<property name="sjina" column="sjina"></property>
		<set name="studentxxbs">
			<key>
				<column name="student_xxbs"></column>
			</key>
		<one-to-many class="model.studentxxb"/>
		</set>
	</class>

</hibernate-mapping>

　　4)测试类 Testmain.java:

　　　　

package test;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import model.studentinfo;
import model.studentxxb;

public class Testmain1 {
	public static void main(String[] args) {
			Session session=new Configuration().configure().buildSessionFactory().openSession();
			 Transaction tt=session.beginTransaction();

			 studentinfo studentinfo=new studentinfo();
			 studentinfo.setName("王胖子");
			 studentinfo.setAihao("爬山");
			 studentinfo.setSjina(new Date());

			 studentxxb xxb=new studentxxb();
			 xxb.setDiz("是是是");
			 xxb.setDhua("1111111");
			 studentinfo.getStudentxxbs().add(xxb);
			 xxb.setStudentinfos(studentinfo);
			 session.save(xxb);
			 session.save(studentinfo);
			 tt.commit();
			 session.close();
	}
}

　　5)控制台运行结果:

　　　　

　

　　6)数据库运行结果:

　　　　　　　　　　

*先导包