如果我在具有時間戳的表中記錄瞭如何查詢,以便每個用戶的每天結果都作爲結果集中的一行獲得,以及來自另一張桌子?在特定時間段內爲每個日期選擇一行
例子:
batch_log
id | userid | batchid | start_time | end_time |time_elapsed
----------------------------------------------------------------------------------
1 | bob | 123sgd |2011-06-23 18:00:00 | 2011-06-23 18:12:00 | 00:12:00
2 | jim | 234sgd |2011-06-22 12:00:00 | 2011-06-22 12:12:00 | 00:12:00
3 | bob | 1234gd |2011-06-23 19:00:00 | 2011-06-23 19:08:00 | 00:08:00
4 | bob | 1Abeds |2011-06-22 19:00:00 | 2011-06-23 20:24:00 | 00:24:00
的screwups
id | userid | time_of_screwup
---------------------------------------------
1 | bob |2011-06-23 19:29:16
2 | jim |2011-06-23 16:29:24
3 | bob |2011-06-22 12:29:16
4 | bob |2011-06-23 13:29:16
如何選擇,這樣我可以同時獲得時間流逝和的screwups每天爲每個人,使數我可以把這個餵給excel。
輸出示例:
userid | date |COUNT(time_elapsed)| COUNT(screwups)|
------------------------------------------------------------
bob | 2011-06-23 | 00:20:00 | 2
jim | 2011-06-22 | 00:12:00 | 1
bob | 2011-06-22 | 00:24:00 | 1
編輯:數據更有意義
對於您的情況,加上GROUP BY DATE('time_of_screwup')可能會很有用。看到http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date – Fabio