Hibernate实例实现(注解方式)添加两张关系表

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1.新建两个实体类Employee.class 和 Company.class

2.新建一个主配置文件 ec-hibernate.xml（注解的方式省去映射文件）

<?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:3306/test</property><property name="connection.username">root</property><property name="connection.password">408817</property><property name="dialect">org.hibernate.dialect.MySQL57Dialect</property><property name="show_sql">true</property><property name="hbm2ddl.auto">update</property><!-- 非注解 <mapping resource="com/jmx/ec/Employee-mapper.xml" /><mapping resource="com/jmx/ec/Company-mapper.xml" /> --><!-- 注解 --><mapping class="com.jmx.ec.Employee" /><mapping class="com.jmx.ec.Company" /></session-factory></hibernate-configuration>

3.Employee.class

package com.jmx.ec;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.ManyToOne;import javax.persistence.Table;import org.hibernate.annotations.CascadeType;import org.hibernate.annotations.Cascade;import org.hibernate.annotations.GenericGenerator;/** * 员工 * */@Entity //实体@Table(name="employee") //表名@GenericGenerator(name="genid",strategy="increment") //主键生成策略public class Employee {@Id@GeneratedValue(generator="genid") //主键生成策略@Column(name="eid")private int eid;@Column(name="ename")private String ename;@ManyToOne@Cascade(value={CascadeType.SAVE_UPDATE})@JoinColumn(name="companyid")private Company company;public Company getCompany() {return company;}public void setCompany(Company company) {this.company = company;}public int getEid() {return eid;}public void setEid(int eid) {this.eid = eid;}public String getEname() {return ename;}public void setEname(String ename) {this.ename = ename;}}

4.Company.class

package com.jmx.ec;import java.util.Set;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.OneToMany;import javax.persistence.Table;import org.hibernate.annotations.Cascade;import org.hibernate.annotations.CascadeType;import org.hibernate.annotations.GenericGenerator;/** * 公司 * */@Entity@Table(name="company")@GenericGenerator(name="genid", strategy="increment")public class Company {@Id@GeneratedValue(generator="genid")@Column(name="cid")private int cid;@Column(name="cname")private String cname;@OneToMany@Cascade(value= {CascadeType.ALL})@JoinColumn(name="companyid")public Set<Employee> employees;public int getCid() {return cid;}public void setCid(int cid) {this.cid = cid;}public String getCname() {return cname;}public void setCname(String cname) {this.cname = cname;}public Set<Employee> getEmployees() {return employees;}public void setEmployees(Set<Employee> employees) {this.employees = employees;}}

最后编写一个测试类：

//读取配置文件Configuration cfg =new Configuration();cfg.configure("ec-hibernate.xml");SessionFactory factory = cfg.buildSessionFactory();Session session = factory.openSession();Transaction transaction = session.beginTransaction();

执行后：

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