这是我的查询:
SELECT
CONCAT( YEAR( prm.fromdt ) , '|', MONTH( prm.fromdt ) ) AS k,
CONCAT( YEAR( prm.fromdt ) , ' - ', MONTH( prm.fromdt ) ) AS v,
FROM prm
GROUP BY k
ORDER BY `k` DESC
返回:
K V
2009|7 2009 - 7
2009|6 2009 - 6
NULL NULL
有没有办法NULL NULL
让我有多少空值?就像是
K V
2009|7 2009 - 7
2009|6 2009 - 6
Nulls 6