hibernate annotation manytoone 单向

三范式：

第一范式：要有主键，列不可分

第二范式：联合范式，不能存在部分依赖

第三范式：不能存在传递依赖

 

解释：一个people对应多个dream

代码如下：

[dream] //many一方

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

@Entity
//@Table(name="m_dream")
public class dream {
 private int id ;
 private String content;
 private people people;  //在many一方生成getter和setter方法
 @ManyToOne  //在many一方加注解 正好是manytoone
 @JoinColumn(name="ss")
 public people getPeople() {
  return people;
 }
 public void setPeople(people people) {
  this.people = people;
 }
 @Id
 @GeneratedValue
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getContent() {
  return content;
 }
 public void setContent(String content) {
  this.content = content;
 }
 
}

 

[people]

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

@Entity
//@Table(name="m_people")
public class people {
 private int id ;
 private String active;
 
 
 
 @Id
 @GeneratedValue
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getActive() {
  return active;
 }
 public void setActive(String active) {
  this.active = active;
 }
 
 
}

 

[test]

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class testUsers {

 @Test
 public void testSchemaExport() {
  SessionFactory sessionFactory = new AnnotationConfiguration()
    .configure().buildSessionFactory();
  SchemaExport export = new SchemaExport(
    new AnnotationConfiguration().configure());
  export.create(true, false);
  Session session = sessionFactory.getCurrentSession();
  session.beginTransaction();
  session.getTransaction().commit();

 }

}

利用反向工程得到的表：