计算特定时间戳记的总记录数

Question

您好我需要构建一个DB2 / SQL查询，以便知道相应时间戳的项目总数。

      Date            Item
 01/08/2014 05:53   request 1 
 02/08/2014 05:53   request 1
 03/08/2014 05:53   request 1
 01/08/2014 06:32   request 2
 02/08/2014 06:32   request 2
 03/08/2014 06:32   request 2
 01/08/2014 06:38   request 3
 02/08/2014 06:38   request 3
 03/08/2014 06:38   request 3
 04/08/2014 06:38   request 3
 05/08/2014 06:38   request 3

我希望以这种方式输出：

         Date             Item       No of Occurences
    01/08/2014 05:53    request 1           3
    01/08/2014 06:32    request 2           3
    01/08/2014 06:38    request 3           5

先谢谢!!

Answer 1

在分组中包括日期：

SELECT Date, Item, count(*) as "No of Occurrences"
FROM <tablename>
GROUP BY Date, Item

Answer 2

使用GROUP BY和COUNT

   SELECT Date, Item, Count(*) "No of Occurences"
   FROM <Table>
   GROUP BY Item