试试这个:

SELECT CustomerID, YearMonth, True_False,
       CASE 
          WHEN True_False = 1 THEN 0
          ELSE ROW_NUMBER() OVER (PARTITION BY True_False, grp 
                                  ORDER BY YearMonth) 
       END AS Sequence
FROM (      
   SELECT CustomerID, YearMonth, True_False,
          ROW_NUMBER() OVER (ORDER BY YearMonth) - 
          ROW_NUMBER() OVER (PARTITION BY True_False 
                             ORDER BY YearMonth) AS grp
   FROM mytable ) AS t
ORDER BY YearMonth

查询计算字段grp，该字段标识具有相同True_False 值的连续记录的岛.在外部查询中使用此字段，我们可以枚举这些岛屿中包含的记录，从而获得所需的序列号.

The query calculates field grp which identifies islands of consecutive records having the same True_False value. Using this field in an outer query we can enumerate the records contained inside these islands and thus get the required sequence number.

此处演示