按多列和时间跨度对MYSQL结果进行分组

如何从今天开始计算，每7天选择一个，最近的NID，从UID开始计算。按多列和时间跨度对MYSQL结果进行分组

如果今天是7月11日见下表

+-----+------------+-----+ 
| NID | timestamp | UID | 
+-----+------------+-----+ 
| 1 | 1341719851 | 8 | //July 7 
| 2 | 1341115051 | 8 | //July 1 
| 3 | 1341547051 | 8 | //July 6 
| 4 | 1341719851 | 8 | //July 8 
| 5 | 1341979051 | 8 | //July 11 
| 6 | 1341806251 | 9 | //July 9 
| 7 | 1341460651 | 9 | //July 5 
| 8 | 1341892651 | 9 | //July 10 
+-----+------------+-----+

将输出这样的：

+-----+------------+-----+ 
| NID | timestamp | UID | 
+-----+------------+-----+ 
| 2 | 1341115051 | 8 | //July 1 
| 5 | 1341979051 | 8 | //July 11 
| 8 | 1341892651 | 9 | //July 10 
+-----+------------+-----+

在过去7天，最近NID为每个用户是'5'和'8'，在前7天，最近的NID是'2'，依此类推......

我假设， Group By将会诀窍;但我不知道从哪里开始。

UPDATE

这是工作的查询的基础上，最多的回答：

SELECT nid, timestamp, uid, weeks_ago 
FROM (
    SELECT nid, timestamp, uid, FLOOR(
     (UNIX_TIMESTAMP()- timestamp)/604800 
    ) weeks_ago 
    FROM `table` 
    ORDER BY timestamp DESC 
) x 
GROUP BY uid, weeks_ago

来源

2012-07-12 timofey

'timestamp'列是MySQL'TIMESTAMP'数据类型吗？这是*滚动* 7天或7天=一周？你想要所有的结果还是仅仅在前7天？ – 2012-07-12 04:32:44

这是一个Unix时间戳......我不知道我是否理解你的权利。这是滚动7天，即从今天0-7天，从今天起8-14天，15-21 ...我需要所有结果，而不仅仅是前7天。 – timofey 2012-07-12 04:54:12

select nid, max(timestamp), uid, weeks_ago 
from (select nid, timestamp, uid, floor(datediff(now(), from_unixtime(timestamp))/7) weeks_ago 
     from mytable) x 
group by nid, uid, weeks_ago

来源

2012-07-12 04:39:45 Barmar

几乎在那里。它输出所有列，不按每个uid的weeks_ago分组。 – timofey 2012-07-12 05:19:30

对这个答案进行了一些调整（查看我的更新，上面），查询工作！谢谢！ – timofey 2012-07-12 06:05:25

select * from (
    (
     select nid, uid,timestamp,floor(datediff(now(), from_unixtime(timestamp))/7) as weeks,from_unixtime(timestamp) as Dt from test t1 order by dt desc limit 0,2) 
Union 
    (
    select nid, uid,timestamp, 
    floor(datediff(now(), from_unixtime(timestamp))/7) as weeks,from_unixtime(timestamp) as Dt 
from test t2 group by weeks having weeks>0 order by dt asc limit 0,1 
    ) 
    ) t4

可能是这样解决您的问题。试试这个

来源

2012-07-12 05:24:28

按多列和时间跨度对MYSQL结果进行分组

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