Question

我有一个包含DeviceData列的表Username, Watts, and CreatedOn，其中CreatedOn的类型为Datetime (yyyy-MM-dd HH:mm:ss)。所有三列都形成一个复合键，并且是Hibernate中的@Embeddable类。

@Embeddable
public class TimeSeriesPowerPK implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private String username;
    private Integer watts;
    private String dateTime;

    public TimeSeriesPowerPK(String username, Integer watts, String dateTime) {
        this.username = username;
        this.watts = watts;
        this.dateTime = dateTime;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getWatts() {
        return watts;
    }

    public void setWatts(Integer watts) {
        this.watts = watts;
    }

    public String getDateTime() {
        return dateTime;
    }

    public void setDateTime(String dateTime) {
        this.dateTime = dateTime;
    }

}

如何在下面显示的DAO中编写查询以检索其creatednn在当前时间与用户输入的小时数或分钟数之间的行的所有Watts值？

public List<Integer> getPowerUsageForUser(String minutes) {
    List<Integer> powerUsedList = sessionFactory.getCurrentSession().createQuery("***query***").list();
    return powerUsedList;
}

非常感谢任何帮助！提前谢谢！

编辑：更新了问题，以检索所有选定行的特定列值。

Answer 1

使用以下代码

public List<TimeSeriesPowerPK> getPowerUsageForUser(String minutes) {
Query query = sessionFactory.getCurrentSession().createQuery("From TimeSeriesPowerPK where dateTime <=:param1 AND dateTime >= :parma2 ");
query.setParameter("param1",currentDateObject);
query.setParameter("param2",userEnteredDateObject);
List<TimeSeriesPowerPK> powerUsedList=query.list();
return powerUsedList;

}

请注意，必须将类的dateTime映射到数据库表的createdOn列。希望它有所帮助。

Answer 2

您可以使用标准

public List<TimeSeriesPowerPK> getPowerUsageForUser() {

        Criteria powerCriteria= session.createCriteria(TimeSeriesPowerPK.class);
        powerCriteria.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);

        powerCriteria.add(Restrictions.le("dateTime",currentDateObject));
        powerCriteria.add(Restrictions.ge("dateTime",userEnteredDateObject));

        return powerCriteria.list();
    }

Answer 3

试试这个

Query qrFetch=ursession.createQuery("from TimeSeriesPowerPK where dateTime between :start_date and :end_date");
qrFetch.setParameter("start_date",currentDateObject);
qrFetch.setParameter("end_date",userEnteredDateObject);
List<TimeSeriesPowerPK> timeSeriesPowerPKList=qrFetch.list();

Hibernate查询以选择Datetime列的时间范围内的行

3 个答案: