sql-server - MSSQL根据时间差计算项目数

Question

我有一个信息表(tbl_results)，如下所示:

name  | time_in_minutes
-------------
jonny | 14
jonny | 27
jonny | 28
jonny | 56
jonny | 57
jonny | 58
sarah | 12
sarah | 16
sarah | 17
sarah | 24
sarah | 25

我很想知道如何编写一个查询(也许是交叉连接？)，它总结了特定时间段内的次数。对于上面的示例，我将使用 10 分钟的计时。所以结果如下。

name  | 0-10 | 11-20 | 21-30 | 31-40 | 41-50 | 51-60
jonny |   0  |   1   |   2   |   0   |   0   |   3
sarah |   0  |   3   |   2   |   0   |   0   |   0 

我会编写一些代码，但我真的不知道从哪里开始这样的查询。

Answer 1

使用条件聚合:

SELECT
    name,
    [0-10]  = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END),
    [11-20] = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END),
    [21-30] = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END),
    [31-40] = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END),
    [41-50] = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END),
    [51-60] = COUNT(CASE WHEN time_in_minutes BETWEEN 0 AND 10 THEN 1 END)
FROM tbl
GROUP BY name