hibernate笔记-011-单向一对多映射

来源：互联网发布：insert into多个数据编辑：程序博客网时间：2024/05/21 01:29

年级（一）->学生（多）

注解配置

package com.hibernate.entity;import java.io.Serializable;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;import org.hibernate.annotations.GenericGenerator;// 学生@Entity@Table(name = "t_student2")public class Student2 implements Serializable {private static final long serialVersionUID = -2005812841024253872L;@Id@GeneratedValue(generator = "student2_gen")@GenericGenerator(name = "student2_gen", strategy = "native")private int id;private String name;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;}}

package com.hibernate.entity;import java.io.Serializable;import java.util.HashSet;import java.util.Set;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.GenericGenerator;// 年级@Entity@Table(name = "t_grade2")public class Grade2 implements Serializable {private static final long serialVersionUID = 554334303764498498L;@Id@GeneratedValue(generator = "grade2_gen")@GenericGenerator(name = "grade2_gen", strategy = "native")private int id;private String name;@OneToMany// 只加 @OneToMany 会生成中间表(多对多的特殊情况)，需要加上 @JoinColumn@JoinColumn(name = "gradeid")private Set<Student2> student2 = new HashSet<Student2>();public int getId() {return id;}public String getName() {return name;}public Set<Student2> getStudent2() {return student2;}public void setId(int id) {this.id = id;}public void setName(String name) {this.name = name;}public void setStudent2(Set<Student2> student2) {this.student2 = student2;}}

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