Hibernate(七)一对一映射

一、创建数据库表

--班级表
create table grade
(
       gid       number           primary key,  --班级ID
       gname     varchar2(50),                  --班级名称
       gdesc     varchar2(50)                   --班级介绍
);
--学生表
create table student
(
       sid       number           primary key,  --主键ID学生ID
       sname     varchar2(20),            --学生姓名
       sex       varchar2(20),            --学生性别
       gid       number           references grade(gid) ---外键班级ID
);

--学生证表
create table paper
(
       pid   number primary key,
       pdesc varchar2(100)  ,
       sid   number references student(sid) not null
       
);

二、创建配置文件和持久化类

学生类

package entity;

/*
 * 学生类
 */
public class Student implements java.io.Serializable {

    // Fields

    private static final long serialVersionUID = 1L;
    private int sid;
    private String sname;
    private String sex;
    //增加班级属性
    private Grade grade;
    //学生证类
    private Paper paper;

    // Constructors

    /** default constructor */
    public Student() {
    }

    /** minimal constructor */
    public Student(int sid) {
        this.sid = sid;
    }

    /** full constructor */
    public Student(int sid, String sname, String sex ) {
    
        this.sid = sid;

        this.sname = sname;
        this.sex = sex;
    }

    // Property accessors

    public int getSid() {
        return this.sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    

    public String getSname() {
        return this.sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    public String getSex() {
        return this.sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Grade getGrade() {
        return grade;
    }

    public void setGrade(Grade grade) {
        this.grade = grade;
    }

    public Paper getPaper() {
        return paper;
    }

    public void setPaper(Paper paper) {
        this.paper = paper;
    }
    

}

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