Question

我有一张表：

 RCD_ID      ID           TIMESTAMP
--------|-----------|---------------------
    1,   2737738826, '2015-10-30 16:19:17'
    3,   2737738826, '2015-10-30 16:22:46'
    4,   2737738826, '2015-10-30 16:24:36'
    5,   2737738826, '2015-10-30 16:29:49'
    7,   2737738826, '2015-10-30 16:40:02'
    9,   2737738826, '2015-10-30 17:11:55'

我需要过滤结果集，以便每条记录的“距离”为20分钟：

 RCD_ID      ID          TIMESTAMP
--------|-----------|---------------------
    1,   2737738826, '2015-10-30 16:19:17'
    7,   2737738826, '2015-10-30 16:40:02'
    9,   2737738826, '2015-10-30 17:11:55'

[错误的问题：哪种方式最好（也是最快）？]

正确的问题：有人可以给我一些建议如何开始吗？

修改

我在表格中添加了一个record_id字段，我尝试了这个查询：

select m.*,
       (select m2.rcd_id 
        from tbl_data m2 
        where (m2.rcd_id > m.rcd_id) AND (TIMESTAMPDIFF(MINUTE, m.log_timestamp, m2.log_timestamp) >= 30)
        order by m2.rcd_id limit 1) as m2
from tbl_data as m

但它会返回所有记录。我是在正确的方式吗？

感谢。

Answer 1

加入桌子（我已经使用了名称＆＃39; logs＆＃39;）给自己，并且只保留那些符合时间限制的记录，例如：

SELECT * FROM logs AS t1, logs AS t2 WHERE t1.ID = t2.ID AND t1.TIMESTAMP != t2.TIMESTAMP AND TIMESTAMPDIFF(MINUTE, t1.TIMESTAMP, t2.TIMESTAMP) = 20

过滤MySQL查询时间戳字段之间的差异

1 个答案: