@Override
public String toString() {
return id + "," + username + "," + number + "," + date;
}
}
最关键的是控制层方法实现类,HQL.java,就是把上面所介绍的Hibernate的聚类查询、分组查询、排序与时间之差查询利用dbDAO.java的封装,一一实现:
?
?
import java.util.*;
@SuppressWarnings("unchecked")
public class HQL {
public static void main(String[] args) {
// 建立DAO类
dbDAO db = new dbDAO();
// 如果返回值是唯一的,则用uniqueResult()方法
String result = db
.query("select count(*) from Testtable t where timestampdiff(year,t.date,now())<30")
.uniqueResult().toString();
System.out.println(result);
System.out.println();
// 排序与聚类查询(分组查询)
List