-- 注意是否会出现NULL值CREATE TABLE DD(CC NCHAR(10),QTY INT) INSERT DD SELECT 'AB',0 INSERT DD SELECT 'CC',5 SELECT * FROM DDCREATE TABLE FF(EE NCHAR(10),QTY INT) INSERT FF SELECT 'CC',0 SELECT * FROM FFSELECT AA,SUM(QTY) AS QTYTOTAL FROM ( SELECT CC AS AA ,QTY FROM DD UNION ALL SELECT EE AS AA,QTY FROM FF )A GROUP BY AA HAVING SUM(QTY)<>0DROP TABLE DD DROP TABLE FF
INSERT DD SELECT 'AB',0
INSERT DD SELECT 'CC',5
SELECT * FROM DDCREATE TABLE FF(EE NCHAR(10),QTY INT)
INSERT FF SELECT 'CC',0
SELECT * FROM FFSELECT AA,SUM(QTY) AS QTYTOTAL FROM
(
SELECT CC AS AA ,QTY FROM DD
UNION ALL
SELECT EE AS AA,QTY FROM FF
)A
GROUP BY AA
HAVING SUM(QTY)<>0DROP TABLE DD
DROP TABLE FF