无论如何都要计算某个时间段内某个值的变化次数。
例如，我的索引中存储了以下信息。
Index Name Result TimeStamp
idx16 A 7 March 7th 2018, 16:17:35.000
idx16 A 7 March 7th 2018, 16:17:36.000
idx16 A 8 March 7th 2018, 16:17:37.000
idx16 A 7 March 7th 2018, 16:17:38.000
idx16 B 1 March 7th 2018, 16:17:35.000
idx16 B 2 March 7th 2018, 16:17:36.000
idx16 B 3 March 7th 2018, 16:17:37.000
idx16 B 7 March 7th 2018, 16:17:38.000
idx16 C 1 March 7th 2018, 16:17:35.000
idx16 C 1 March 7th 2018, 16:17:36.000
idx16 C 1 March 7th 2018, 16:17:37.000
idx16 C 1 March 7th 2018, 16:17:38.000
所需的结果是A改变2，B改变3，C改变0次？