如果值不匹配，我如何计算记录和中断？

Question

我有这张表的记录

   No  |  Part | value |
------ | ------|------ |
   1   |   A1  |   2   |
   2   |   A1  |   2   |
   3   |   A1  |   1   |
   4   |   A1  |   2   |
   5   |   A1  |   2   |
   6   |   A1  |   2   |

当值不匹配时，我可以计算最后一条记录和中断/结束计数吗？

例如计数值等于2，计数结果为3

Answer 1

我怀疑您的意思是相邻值的计数相同。在 SQL Server 2005 中，您可以使用行号的差异来做到这一点：

select count(*)
from (select value, (seqnum - seqnum_v), grp, count(*) as cnt
      from (select t.*,
                   row_number() over (partition by part order by id) as seqnum,
                   row_number() over (partition by part, value order by id) as seqnum_v
            from t
           ) t
      group by value, (seqnum - seqnum_v)
     ) t;