Question

我有以下表格数据：

    +-----+---------------------+---------------------+------------+--------+------+-----------------+
    | id  | date_timer_off      | date_timer_on       | event_done | device | user | admin_email     |
    +-----+---------------------+---------------------+------------+--------+------+-----------------+
    | 145 | 2017-03-08 16:54:00 | 2017-03-08 16:55:00 | T          |      3 |    4 | admin@admin.com |
    | 146 | 2017-03-08 16:54:00 | 2017-03-08 16:55:00 | T          |      4 |    4 | admin@admin.com |
    | 147 | 2017-03-08 16:54:00 | 2017-03-08 16:55:00 | T          |      5 |    4 | admin@admin.com |
    | 148 | 2017-03-08 16:55:00 | 2017-03-08 16:56:00 | T          |      3 |    4 | admin@admin.com |
    | 149 | 2017-03-08 16:55:00 | 2017-03-08 16:56:00 | T          |      4 |    4 | admin@admin.com |
    | 150 | 2017-03-08 16:55:00 | 2017-03-08 16:56:00 | T          |      5 |    4 | admin@admin.com |
    | 151 | 2017-03-08 18:28:00 | 2017-03-08 18:29:00 | T          |      3 |    4 | admin@admin.com |
    | 152 | 2017-03-08 18:28:00 | 2017-03-08 18:29:00 | T          |      4 |    4 | admin@admin.com |
    | 153 | 2017-03-08 18:28:00 | 2017-03-08 18:29:00 | T          |      5 |    4 | admin@admin.com |
    | 154 | 2017-03-08 18:32:00 | 2017-03-08 18:33:00 | F          |      3 |    4 | admin@admin.com |
    | 155 | 2017-03-08 18:32:00 | 2017-03-08 18:33:00 | F          |      4 |    4 | admin@admin.com |
    | 156 | 2017-03-08 18:32:00 | 2017-03-08 18:33:00 | F          |      5 |    4 | admin@admin.com |
    | 157 | 2017-03-08 18:58:00 | 2017-03-08 18:58:00 | F          |      3 |    4 | admin@admin.com |
    | 158 | 2017-03-08 18:58:00 | 2017-03-08 18:58:00 | F          |      4 |    4 | admin@admin.com |
    | 159 | 2017-03-08 18:58:00 | 2017-03-08 18:58:00 | F          |      5 |    4 | admin@admin.com |
    | 160 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      3 |    4 | admin@admin.com |
    | 161 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      4 |    4 | admin@admin.com |
    | 162 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      5 |    4 | admin@admin.com |
    +-----+---------------------+---------------------+------------+--------+------+-----------------+

我需要的结果如下：

    +-----+---------------------+---------------------+------------+--------+------+-----------------+
    | id  | date_timer_off      | date_timer_on       | event_done | device | user | admin_email     |
    +-----+---------------------+---------------------+------------+--------+------+-----------------+
    | 160 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      3 |    4 | admin@admin.com |
    | 161 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      4 |    4 | admin@admin.com |
    | 162 | 2017-03-08 19:02:00 | 2017-03-08 19:03:00 | F          |      5 |    4 | admin@admin.com |
    +-----+---------------------+---------------------+------------+--------+------+-----------------+

只有在event_done状态为“F”或其他字母为false时，才需要在表格中仅返回每个设备ID的最新一条记录。

记录也必须在发出请求的当前分钟内，因为将每20秒查询一次数据库以更新定时器列表。

例如，如果请求是在19:02:20进行的，则应检查以检查date_timer_off或date_timer_on字段是否在请求发出的时间内（19:02:20），从而返回上述内容结果集。

我尝试实施这篇文章SQL query for returning the latest record for each ID的答案，但没有成功。

这是我在生产环境中使用的当前查询，但它会导致下一个事件无法触发等问题。

    select * from timers_data data where data.date_timer_off >= :today AND data.date_timer_off <= :tomorrow AND data.date_timer_on >= :today AND data.date_timer_on <= :tomorrow AND data.event_done = 'F' ORDER BY data.id DESC

我也试过这个：

    select * from timers_data where event_done = 'F' and (date_timer_off >= now() or date_timer_on >= now()) ORDER BY id desc;

它在MySQL上运行时有效，但是当我使用Spring的JPA CrudRepository在我的Spring应用程序中运行它时似乎有问题，如下所示：

    @Query(value = "select * from timers_data where event_done = 'f' and (date_timer_off >= now() or date_timer_on >= now()) ORDER BY id desc;", nativeQuery = true)
    ArrayList<TimersData> findTimersForToday();

这是我目前在项目中使用的内容：

    @Query(value = "select * from timers_data data where data.date_timer_off >= :today AND data.date_timer_off <= :tomorrow AND data.date_timer_on >= :today AND data.date_timer_on <= :tomorrow AND data.event_done = 'F' ORDER BY data.id DESC", nativeQuery = true)
    ArrayList<TimersData> findTimersForToday(@Param("today") Date today, @Param("tomorrow") Date tomorrow);

任何帮助将不胜感激。

提前致谢

Answer 1

您可以使用带有in子句的subselect，该子句基于与设备匹配的元组和max（date ..）

select  * from  timers_data data 
where (device, date_timer_off) in ( 
     select device, max(date_timer_off)
     from timers_data data 
     where data.date_timer_off >= :today 
     AND data.date_timer_off <= :tomorrow 
     AND data.date_timer_on >= :today 
     AND data.date_timer_on <= :tomorrow 
     AND data.event_done = 'F' 
    group by device ) 
ORDER BY data.id

返回表中每个设备ID的单个最新记录

1 个答案: