用group by啊,
如:SELECT AA, COUNT(1) AS NUM
FROM (SELECT 'A' AA
FROM DUAL
UNION ALL
SELECT 'A'
FROM DUAL
UNION ALL
SELECT 'B'
FROM DUAL
UNION ALL
SELECT 'A'
FROM DUAL
UNION ALL
SELECT 'C'
FROM DUAL
UNION ALL
SELECT 'B' FROM DUAL) T
WHERE T.AA IN ('A', 'B')
GROUP BY AA