Hiberate CRUD操作
@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
这段代码将ID设置成自动生成ID的策略,如果是自己手动创建数据库,注意要将id自动设置为auot_increment,否则将会报如下错误:
Field 'id' doesn't have a default value
设定Id自动生成,也需要把get和set方法设置好,然后在get方法前面加上@Id,@GenratedValue来进行
============================
自动创建表
public static void main(String[] args) { //自动创建表格,第一个true:是否显示创建表的语句。 new SchemaExport(new AnnotationConfiguration().configure()).create(true, true); Student s = new Student(); s.setName("laichunbin"); s.setAge(20); s.setAddress("hellworld"); Configuration config = new AnnotationConfiguration(); SessionFactory sf = config.configure().buildSessionFactory(); Session session = sf.openSession(); session.beginTransaction(); session.save(s); session.getTransaction().commit(); session.close(); s.setId(1); s.setName("championl"); Session session2 = sf.openSession(); session2.beginTransaction(); session2.update(s); session2.getTransaction().commit(); session2.close(); // Student s2 = new Student(); // s.setId(2); // Session session3 = sf.openSession(); // session3.beginTransaction(); // Student g = (Student)session3.get(Student.class,1); 加载对象,通过id来获取 // Student g2 = (Student)session3.load(Student.class,4); // System.out.println(g); // System.out.println(g2); // session3.getTransaction().commit(); // session3.close(); }
posted on 2014-08-03 11:35 Champion Lai 阅读(179) 评论(0) 编辑 收藏 举报