private String name;//注解写于getter方法之上.请见下.

//DATE            - java.sql.Date        
     //TIME            - java.sql.Time        
     //TIMESTAMP - java.sql.Timestamp        
     @Temporal(TemporalType.TIMESTAMP)        
     @Column(name="start_time")        
     private Date startTime;

//显示0 隐藏1        
     public static enum DisplayType {显示,隐藏}        
     @Enumerated(value = EnumType.ORDINAL)//ORDINAL序数        
     private DisplayType displayType = DisplayType.显示;

//1.sql语句中的字段和表名都应该和数据库相应,而不是类中的字段,        
     //若带有参数如la.id= id,这个=id才是类中属性        
     //2.操作字段一定要用别名        
     @Formula(select COUNT(la.id) from largess la)        
     private int count;

//注解于方法中 
        @Column(name="PLANE_ID", length=80, nullable=true) //较详细定义 
        public String getName() { 
                return name; 
        } 
        public void setName(String name) { 
                this.name = name; 
        } 
其它的setter,getter省略...... 
}

package oneToMany; 
import javax.persistence.*; 
@Entity 
@Table(name="student") 
public class Student implements Serializable  { 
  @Id 
  @GeneratedValue(strategy=GenerationType.AUTO) 
  private int sid; 
    
  private String sname; 
    
  //若有多个cascade，可以是：{CascadeType.PERSIST,CascadeType.MERGE} 
  @ManyToOne(cascade={CascadeType.ALL})         
  @JoinColumn(name="classid")     //student类中对应外键的属性：classid 
  private Classes classes; 
//getter,setter省略 
}

public class TestOneToMany { 
/* 
CREATE TABLE    student (    --要定义外键!!!!!!! 
    `sid` double NOT NULL auto_increment, 
    `classid` double NULL, 
    `sname` varchar(255) NOT NULL, 
    PRIMARY KEY    (sid), 
    INDEX par_ind (classid), 
    FOREIGN KEY (classid) REFERENCES classes(id) ON DELETE CASCADE ON UPDATE CASCADE 
) ENGINE=InnoDB 
*/    
  public static void main(String[] args) throws SQLException    
  { 
    try 
    { 
      SessionFactory sf = new AnnotationConfiguration().configure().buildSessionFactory(); 
      Session session=sf.openSession(); 
      Transaction tx=session.beginTransaction();