获取队列重复相同的值计数

Given table/data like this:

给出这样的表/数据:

WITH T(col1, col2) AS(
    SELECT 1, 'A' FROM DUAL
    UNION ALL
    SELECT 2, 'B' FROM DUAL
    UNION ALL
    SELECT 3, 'B' FROM DUAL
    UNION ALL
    SELECT 4, 'B' FROM DUAL
    UNION ALL
    SELECT 5, 'A' FROM DUAL
    UNION ALL
    SELECT 6, 'B' FROM DUAL
    UNION ALL
    SELECT 7, 'B' FROM DUAL
    UNION ALL
    SELECT 8, 'A' FROM DUAL
)
WITH